Some argue that the best way to confront an enemy is to face him head on. At times, however, a belligerent realizes that he cannot strike the enemy directly because he is not strong enough, it involves unacceptable risks, or he believes greater gains can be made by opening a “second front.” The purpose of second front operations may be to strike a blow to enemy strength, gain resources such as oil while denying them to the enemy, split the enemy alliance by knocking out a weaker member, assist an ally under attack by diverting the enemy, or influence a third party, perhaps deterring that party from entering the war.
Following are four examples of such second front maneuvers. Two succeeded and two failed. These operations have implications for the way America will fight for the foreseeable future. Our wars are now wars of choice, and the motives and constraints driving such conflicts are comparable to those of belligerents seeking to open second fronts throughout history.
The Sicilian Expedition During the Peloponnesian War
The Peloponnesian War between Athens and Sparta was in its 16th year when Athens decided to invade Sicily. Its rationale for invasion concerned Egesta—a city-state in western Sicily allied with Athens. It was being harried by Selinus, a nearby city, and asked the Athenian Assembly to send aid while also warning of Syracuse, the most powerful city-state on Sicily. Syracuse, the envoys claimed, was bent on dominating the entire island and was friendly toward Sparta. This meant that Sparta would have access to huge resources in grain, soldiers, and ships, resources that could be used against Athens.1
Such catastrophizing on what might occur was hardly a justification for war. Nonetheless, the Athenians, led by a gifted scoundrel named Alcibiades, pushed for an invasion of Sicily to defeat Syracuse and conquer the island.2
Nicias warned that an expedition made little strategic sense. It would anger Sparta, which had an uneasy truce with Athens, and involve a major war with Syracuse, a useful trading partner. The expedition would involve enormous risk but offer little gain. In a prescient comment, Nicias stated: “I affirm . . . that you leave many enemies behind you here [the Spartans and their Corinthian allies] to go there far away and bring more back with you.”3 Nicias urged his fellow citizens to focus on Sparta, the main threat close at hand. Alcibiades argued instead that Sicily would be an easy conquest that would heap glory on Athens while intimidating Sparta. Alcibiades was the more persuasive.4
The invasion was launched in 415 BCE. Nicias, Alcibiades, and Lamachus were chosen as joint commanders, and 136 warships—carrying 5,100 hoplites but only 30 horses—set sail.5 Soon after landing in Sicily, Alcibiades was recalled to Athens to stand trial on charges of blasphemy.6 Believing he would be found guilty, Alcibiades fled to Sparta and offered his services.
Thucydides argues that had the Athenians moved quickly, they would have overcome Syracusan resistance. Instead, they dallied, partly because of Alcibiades’s recall and partly due to the cautiousness of Nicias. Things quickly turned sour. Egesta did not have the promised money. Horses were in short supply so the army had little cavalry. The Sicilians did not welcome their liberators and instead the Athenian force united Sicily as nothing else could have.7 The Syracusans proved tough adversaries, especially after Sparta sent one of its generals, Gylippus, to assist them, along with a contingent of Corinthian hoplites. Sparta then invaded Attica, the area surrounding Athens, and laid it to waste. As Nicias predicted, Athens was fighting a two-front war against two formidable opponents.
Nicias, the sole commander after the departure of Alcibiades and the death of Lamachus in battle, continued to delay, pleading for either reinforcements or evacuation. The Assembly sent another army but it made little difference. In 413, Gylippus defeated the Athenians, Nicias was butchered, and at least 7,000 Athenians were captured and enslaved. It was a horrendous loss.8
Athens saw this as a preventive war to abort the presumed union of Sicily and Sparta against it. But there was little indication such an alliance would have occurred. Indeed, it was the expedition itself that drove Syracuse into the arms of Sparta.
Wellington in the Peninsula
After the Peace of Tilsit in 1807, Napoleon controlled most of Europe. Britain still held out, and in an effort to break its economy, Napoleon instituted the Continental System. He ordered Europe not to trade with Britain, hoping this policy would so injure the British economy as to force surrender.9 A tiny country on the periphery of Europe, Portugal, refused to obey Napoleon’s decree.10 To teach it a lesson, the Emperor sent 30,000 men to conquer it, and they took Lisbon on November 30, 1807.
Napoleon then installed his brother Joseph on the Spanish throne. To his surprise, the Spanish population rose up against him in May 1808. This resistance movement, one of the bloodiest and most effective guerrilla wars in centuries, became a long-term drain on French resources. The “Spanish Ulcer” lasted for 6 years.11
The French army sent to pacify Spain initially numbered 120,000 and was led by proven commanders. In July 1808, however, an army of 18,000 surrendered to the Spanish at Bailen. Europe was stunned; it was the first surrender by a French army in 7 years. Napoleon was furious: “I realize that I must go there myself to get the machine working again.”12 By October 1808, he would have 270,000 men in Iberia.
A British army under Lieutenant General Arthur Wellesley landed in Portugal in 1809 and built formidable fortifications there. From this sanctuary he repulsed French assaults.13 Wellesley was aided by the tenacity of the Spanish army, which struck continually at the French and their supply lines. Indeed, 70 percent of all French casualties sustained during the war were inflicted by the Spanish army and guerrillas.14 Throughout 1810 and 1811, Wellesley (soon to be the Duke of Wellington) coordinated with the Spanish to pressure the French. It was a hard-fought war, but everything changed in 1812.
Napoleon invaded Russia that year with an army of 500,000. Iberia was then a sideshow. Wellington invaded Spain and over the next year won a series of battles, liberating Madrid in August. The following year, Wellington crossed through the mountains and invaded France. By then Napoleon was fighting for his throne in Germany, a fight he would soon lose.
Napoleon’s foray into Iberia was a huge miscalculation. The French suffered 250,000 casualties, a high price for a failed effort. At the same time, the war occupied 200,000 troops annually that France desperately needed against Russia, Austria, and Prussia in Central Europe. Spain was truly an ulcer that bled the Napoleonic Empire white.
World War I deteriorated into a blood bath by the end of 1914, and a line of trenches stretching from the North Sea to Switzerland induced a stalemate.15 Britain suggested breaking the impasse by opening a second front. The First Lord of the Admiralty was Winston Churchill and the First Sea Lord was Admiral “Jackie” Fisher.16 Their plan was a move against the Dardanelles, the narrow strait separating the Mediterranean from the Black Sea. Constantinople (modern-day Istanbul), the capital of the Ottoman Empire, was located along this waterway. Churchill opined that a move up the strait would push the Turks out of the war. That would in turn open a supply line to Russia and allow a venue from which to strike Austria-Hungary from the rear.
Churchill believed a navy-only operation would suffice to force the strait.17 This passage was flanked on the north by the Gallipoli Peninsula and on the south by the Anatolian mainland. Both coastlines were littered with forts and artillery positions.18 Nonetheless, he thought the big guns of battleships would quickly silence the enemy cannon. The strait was also heavily mined. No matter, the armada would include minesweepers to clear the way. The battleships would confront Constantinople and shell it if necessary and then accept the Ottoman surrender.
A fleet was raised consisting of 82 ships including 18 battleships.19 On February 19, 1915, warships entered the strait and began shelling the forts. It was expected the enemy guns, numbering over 230, would be silenced by naval gunfire within a month. That first day, however, no enemy guns were destroyed despite a barrage lasting 7 hours.20 Several more forays were launched into the straits but achieved meager results. Clearly, naval gunfire was insufficient to knock out heavily defended forts.
On March 18, 1915, the ships went in again but this time they hit mines. Three battleships were sunk and three others were heavily damaged. A third of the Allies’ capital ships were put out of commission in a day. Attempts to remove the mines at night were unsuccessful. The Turks used searchlights to illuminate the trawlers being used as minesweepers and shore guns drove them back.21
A naval-only operation was thus impossible. Churchill then requested an invasion force to capture the Gallipoli Peninsula and overrun the forts from the land side. The fleet could then move safely through the straits. Fisher agreed, arguing that the British effort must be totus porkus (whole hog).22 The high-gain/low-risk navy-only assault had now become a high-risk joint operation.
In April 1915, a force of over 62,000 British and French soldiers landed at Gallipoli.23 They were met by rugged terrain, strongly entrenched positions, and spirited and well-led Turkish defenders. For 8 months, the opposing sides hammered away at each other. Trenches were dug, barbed wire was strung, and the Gallipoli battlefield resembled the Western Front that the entire operation was intended to bypass. Five more Allied divisions were sent, to no avail. Admitting defeat, the Allies evacuated in December 1915.
Overall, the Gallipoli operation was a disaster for the Allies. It cost nearly 400,000 casualties and gained virtually nothing. The Ottoman Empire remained in the war, Russia remained largely cut off from its allies, and the Western Front remained stagnant.
North Africa, Operation Torch, 1942
When the United States entered the war against Germany in December 1941, Allied fortunes were at low ebb. Most of Europe was under Axis control and the Soviet Union was reeling. In the Pacific, Singapore was about to fall to the Japanese as were the Philippines and Dutch East Indies. The Allies needed victories.
The American and British combined chiefs of staff met, confirmed a “Europe First” strategy, and discussed taking the offensive. General George Marshall, the U.S. Army Chief of Staff, argued for a landing in France in the fall of 1942.24 The British refused. They had already been forced to evacuate at Dunkirk and had no wish to retreat again. Although Moscow was screaming for a second front, it would be of little avail if it were thrown back into the sea.25 They wanted an invasion of North Africa instead. It would not only be easier, but it would also allow the green American troops to gain experience and ensure the safety of Egypt and the Suez Canal. Operation Torch was approved.26
Lieutenant General Dwight Eisenhower was chosen to command the operation, largely because American troops would supply the bulk of the invasion force. He advocated landings at Casablanca and Oran. The British disagreed with this limited vision, maintaining that once the Nazis saw the invasion, they would rush troops into Tunisia and block the Allies from moving east and linking up with the British Eighth Army in Libya. Instead, the British wanted additional landings at Algiers, Bone, and Philippeville in Algeria. This would put Allied troops close to Tunisia, allowing them to move in quickly and forestall a Nazi advance. A compromise was reached: besides Casablanca and Oran, the Allies would land at Algiers—500 miles from Tunis.27
North Africa was under the control of Vichy France and heavily defended.28 The French were distrustful of the British; they felt they had been left in the lurch during the battle for France, and the British attacks on their fleet at Mers-el-Kebir in July 1940 were deemed an outrage.29 Eisenhower kept British troops out of the vanguard of the attacks lest they spur a spirited defense.
The invasion took place on November 8, 1942. French resistance was short-lived, and within 3 days Morocco and Algeria were subdued. Unfortunately, the decision to forego landings farther east proved problematic, as the British anticipated. While the Allies were securing their landing areas, German forces flooded into Tunisia. At the time of the Allied landings, there were 11,000 Axis troops in Tunisia; 6 weeks later there were over 47,000.30 A bitter battle would be required to drive them back. Tunisia finally fell on May 13, 1943, and the campaign was over. The Allies suffered 75,000 casualties, but the Axis had over five times that number including 275,000 who became prisoners of war.31
The invasion of North Africa was one of the more successful examples of a second front operation. The goals of the Allies were fulfilled. Torch produced precisely the type of incremental successes such operations were designed to achieve.
The dominant reason for opening a second front is to avoid an enemy’s strength. If the enemy elects to defend vigorously at the new venue, he must often disperse his forces. Gaining an economic advantage can also be a major motive, and this was a partial explanation for the Sicilian Expedition. Similarly, Britain saw Iberia as a major trade market after Napoleon shut down most of Europe to its merchant fleet. Sometimes, financial gain does indeed accompany such operations, but often they cost far more than they earn. Another motive for a second front is an attempt to split an alliance. This was one goal of the British and French at Gallipoli in 1915 when they hoped to force the Ottoman Empire out of the war. Other operations, such as Torch in 1942, were a combination of several motives: driving Axis forces out of North Africa, securing the Mediterranean Sea and Suez Canal, and providing experience for American troops and commanders. These objectives were achieved, although the campaign to capture Tunisia was unnecessarily difficult and protracted.
Now we turn to some overall observations of the case studies described that will shed light on specific factors that helped lead to either success or failure in these flanking maneuvers.
Success versus Failure
Logical and Achievable Strategic Plan. The first and most important
determinant of a second front’s success is the logic and achievability of its aim. In some cases, goals are well thought out—for instance, the decision to launch Torch in 1942 and the Peninsular Campaign during the Napoleonic wars.
Other goals make less sense. The Sicilian Expedition of 415 BCE is an example of poor strategic vision; it was not obvious how the invasion would impact the main enemy, Sparta. Syracuse, although friendly to Sparta, had never taken up arms against Athens. Sending an army to Sicily denuded Athens of an adequate defensive garrison, leaving it prey to Spartan attack—which indeed occurred. In short, given the risk involved, what was the expected payoff? Even if the invasion had been successful, it is not obvious what gains would have accrued to Athens in its war with Sparta.
In some instances, the objectives sought appear worthwhile, but their achievability is questionable. The Gallipoli operation of 1915 looked reasonable at first glance, but it had glaring flaws. It is notoriously difficult for ships to compel the surrender of a defended fortress—much less an entire nation—but Royal Navy leaders pushed aside such details and launched the assault anyway. Reinforcing failure, the Allies upped the ante and committed several divisions of ground troops in a futile attempt to correct earlier misjudgments. The result was an even greater failure.
Accurate Net Assessment. A net assessment is the cost-benefit analysis done prior to a military operation that includes intelligence on the enemy’s positions, strengths, supply lines, armament, and so forth, but also notes the strengths and weaknesses of one’s own forces. It should contain a weighing of goals against expected costs.
The Athenian assessment was faulty. Not only did Athens not encounter a friendly population, but the horses, troops, and money promised by the Egestaeans were never forthcoming. The Athenians were duped.32 They also overestimated the willingness of Sicilian city-states to support an attack on Syracuse.
Napoleon overestimated Spain’s value, believing it to be fabulously wealthy. In truth, Madrid was nearly bankrupt. Moreover, establishing Joseph on the throne was a huge error. The Spanish king may have been an imbecile, but he was Spanish. Napoleon could install a Frenchman on the throne, “but he could not give him popular support.”33 In addition, Spain was incapable of supporting a large army; it was an old adage that “large armies starve in Spain and small ones are defeated.” Supplying a French army over the Pyrenees proved to be a monumental problem.34
The net assessment conducted by the British at the Dardanelles in 1915 was poor. They underestimated the strength of the Turkish forts, the difficulty of knocking out coastal fortifications with naval guns, the impossibility of using trawlers (manned by civilians no less) to sweep mines in the narrow waters with hundreds of enemy guns on both coasts, the horrendous terrain waiting on Gallipoli, and the determination of the Turkish defenders.35
The Allies’ assessment was unusually accurate for Torch, helped much by the breaking of German top-secret codes—“Ultra” intelligence transmitted on Enigma machines. The Allies knew where Axis troops were located and how they were equipped. More importantly, they possessed insight into Vichy French forces and leaders in Northwest Africa, which was crucial for the landings’ success.36
Leadership. Leadership at all levels was crucial in determining success or failure. In Sicily, once Alcibiades fled and Lamachus was killed, Nicias was too hesitant and pessimistic. He had not supported the expedition in the first place, and his penchant for delay meant that his forces were ever on the defensive.
French generals in the Peninsular Campaign had never encountered such austere conditions or endured such relentless guerrilla warfare. Most could not adapt.37 On the other hand, Wellington was an excellent general, although it must be noted that in the Peninsular Campaign he never had to face the best French commander—Napoleon himself. On one occasion, Wellington commented after a hard-fought victory that “If Boney had been there we should have been defeated.”38
Allied leadership at Gallipoli was mediocre and slow to react. In February 1915, there were only two Turkish divisions deployed along the strait; that number doubled by the time the naval assault began, but there were still only six divisions at the time of the major landings. Unfortunately, the Allies were equally dilatory. B.H. Liddell Hart railed against the piecemeal application of force: “If the British had used at the outset even a fair proportion of the forces they ultimately expended in driblets, it is clear from Turkish accounts that victory would have crowned the undertaking.”39 In addition, the Admiralty staff in London did not offer realistic plans for how to reduce the forts or overcome the more than 400 underwater mines within the strait.
Victory was not inevitable in North Africa. American commanders were either untested or prone to mistakes. Eisenhower, who had no combat experience, was a consummate planner, but even there he showed a lack of vision and a tendency to conservatism. His original intent of landing only at Oran and Casablanca was insufficient. After the success of the landings at Algiers he procrastinated in his move toward Tunis, and the delay prolonged the campaign and cost thousands of casualties.40
Intelligence. The Athenians were bereft of suitable intelligence on landing in Sicily. The populace saw them as invaders and instead channeled information to Syracuse. Similarly, the French in the Peninsular Campaign were denied information on the dispositions and intentions of the British, Spanish, and Portuguese. The enemy populations hated the French and served not only as guerrillas to harry supply lines, but were also ruthless in tracking down and killing French spies and couriers.41
In World War II, the Allies broke the top-secret German codes early in the conflict. This ultra-secret intelligence was fundamental in staying ahead of the Germans. At Alamein, for example, Bernard Montgomery was provided with detailed information on the status and dispositions of the entire German and Italian defensive positions as well as, most importantly, their fuel situation.42
Good military commanders appreciate the importance of intelligence to the success of their operations. Great military commanders work to ensure they actually have timely and accurate intelligence. Intelligence is always a key to victory, and the commander’s attitude and personal involvement in the intelligence process are crucial.
Friendly Population. It is difficult for any invader to launch an amphibious operation against a defended shore. Largely because of that the North African invasion was a gamble. Allied leaders predicted barely a 50 percent chance of success. Once ashore, the invader must move quickly to ensure the enemy is unable to concentrate his forces and drive him back into the sea.
Even if the landings are unopposed, an attacker is still not free of care. He must establish a firm base that will permit resupply. Wellington enjoyed such a base in Portugal, which allowed him to operate at some depth into Spain and eventually in France itself. The opposite was the case for France. The French could not ignore the Spanish army that constantly appeared in their rear and along their lines of supply, making it impossible to marshal their full strength against Wellington.43
It was not necessary to win over the population and make them allies, although as noted this occurred in Iberia and was a major factor in British success. The Arab populace in North Africa was indifferent to who occupied the country in 1942, and the Vichy French were easily won over, thus making Allied operations significantly easier.
Force Size. It is an aphorism that attacking an enemy in a defended position requires a three-to-one superiority. Surprisingly, that superiority has not always been present. At Gallipoli, the Allies fed in divisions in a piecemeal fashion. This slow buildup allowed the Turks to simultaneously increase their own defensive forces, with the result that the Allies were never able to establish superiority over the enemy defenders—the Turks eventually had 15 divisions in defense to the 12 divisions of the Allies.
During the Allied invasion of North Africa, there was some concern over the resistance that would be offered by the Vichy French defenders, but Allied intelligence, which proved accurate, placed such resistance at an acceptable level. Moreover, the 200,000 American and British troops hitting the beaches in Morocco and Algeria were sufficient to overawe the French defenders into but a token fight. The argument over the venue for the second front—France versus North Africa—was an important one for this very reason. The French coast would be defended by first-rate German troops, and that presented an entirely different level of risk.
Command of the Sea. In all of the second front examples noted, command of the sea was a significant factor in success. Sea control was crucial to Wellington because most Spanish roads were appalling. The fleet allowed the British to be supplied with food, ammunition, and reinforcements constantly. The Royal Navy did more, providing fire support to army units operating close to shore, resupplying allied coastal fortresses under siege while blockading those held by the French, and serving as a rapid and efficient transportation service for Wellington’s troops.44 But sea supremacy was not enough to guarantee victory. The Athenians had the greatest fleet in Greece during the Peloponnesian War, yet that advantage did not provide victory in Sicily because Athens was unable to exploit it.45 The fleet could not effectively blockade Syracuse itself and thus did not prevent its resupply and reinforcement from Sparta and Corinth.46
Similarly, command of the sea was seemingly assured at Gallipoli, but that was not really the case. There are two aspects to sea control. First, the enemy is prevented from using the sea either to resupply himself or to attack the commerce or warships of the stronger power. The Royal Navy fulfilled that requirement. The second aspect is often overlooked: the enemy is unable to halt the offensive actions of the attacker. Defeating the enemy’s fleet is not an end in itself; control of the sea must then be exploited. That was impossible at Gallipoli because Turkish land-based defenses and mines prevented the Royal Navy from forcing the straits and achieving victory.
In sum, naval superiority was an essential but insufficient factor in the success of these operations.
Command of the Air. World War II demonstrated from its outset that control of the sea was difficult to maintain if the air above the sea was not controlled. During the 1940 Norwegian campaign, the Royal Navy realized on the first day that its ships were extremely vulnerable to the Luftwaffe. Royal Air Force aircraft based in Britain did not have the range to extend an air control bubble over the landing areas. The aircraft of the Fleet Air Arm had reasonable range, given that the Royal Navy’s carriers were in Norwegian waters; however, they were obsolescent compared to Luftwaffe aircraft.47
Operation Torch similarly illustrated the importance of control of the air. It was not coincidental that a key objective at all landing sites on November 8 was to secure airfields for Allied use.48 For the rest of the war, commanders realized that amphibious operations could not succeed if the enemy controlled the air regardless of the size of the flotilla supporting the landings. American amphibious assaults in the Pacific were dependent on air superiority; it was by design that General Douglas MacArthur’s “island-hopping” campaign consisted of 300-mile hops; that was the radius of U.S. fighter aircraft at the time. Air superiority was no less crucial in Europe. Eisenhower considered it a prerequisite and would later testify before Congress regarding the importance of air superiority for the Normandy invasion, stating it was the “deep-seated faith in the power of the air forces, in overwhelming numbers, to intervene in the land battle” that made the landings successful.49
The decision to open a second front against a powerful enemy is a time-tested strategy used for millennia. It provides a less risky option when fighting a powerful opponent while at the same time offering a chance for surprise and initiative. Some of these operations have been successful throughout history while others have not. The above examples offer reasons for success or failure.
Since World War II, the United States has fought wars of choice, not necessity. Korea, Vietnam, Iraq, and several lesser operations were entered as responses to aggression against allies or strategically situated nations/populations we chose to protect. These actions were similar to second front operations based on the motives and constraints involved—a deliberate decision to either limit American commitment or avoid initiating a major war.
The terrorist attacks of September 2001 necessitated a strong response. Even so, it was disastrously faulty intelligence that pushed the United States into an invasion of Iraq. That war, plus Afghanistan peacekeeping operations, employed substantial resources in troops and material, but any results gained were dearly bought over an unusually long time.
Our melancholy experience in the Middle East over the past decade stands in contrast to the wisdom and economy of second front operations that were characterized by restraint. Such caution is increasingly necessary. The American use of force is now characterized by limited liability and a deliberate effort to avoid casualties. The latter, significantly, applies not just to our own forces, but those of the enemy as well. Because the United States is attempting to shape events in foreign countries, it is imperative that it not employ or provoke so much force that the populace is turned against us.
These unusual objectives and limitations push us toward military responses similar to those that dictated second front operations of the past. We wish to avoid taking on an enemy too directly—continued presence should be avoided; risk must be minimized; casualties, especially to the civilian populace, must be severely limited.
As in second front operations, the keys to success are similar and seemingly timeless: the necessity of a clear and achievable strategic goal, the completion of a sound net assessment, accurate and detailed intelligence both before and during the operation, capable if not exceptional leadership at all levels, a sound base and friendly populace, and both sea and air control.
Because American interventions are now almost exclusively expeditionary, the United States must have a robust capability to project power worldwide quickly and sustainably. Sea- and airpower control are essential to protecting those long lines of communication. So too, sea-, air-, and space-based intelligence and communications assets are imperative. In addition, the unique flexibility of airpower, whether land- or sea-based, allows extremely rapid and long-range employment combined with highly accurate and tunable force application. The action in Libya was intended to remove a brutish dictator and give the populace a chance for democracy, but like Kosovo in 1999, it did not involve the use of ground troops in combat.
As the last of our ground forces prepare to leave Afghanistan, it seems increasingly unlikely that America will consider injecting such conventional troops back into a hot area—the costs and risk are simply too high. Instead, we should take a page from the successful second front operations of the past. We should maximize the attributes of our sea and air forces, which can project enormous but discrete power over great distances at relatively low cost and considerably less risk. JFQ