According to realism, the dominant form of American international relations theory since the discipline first emerged, countries act primarily in response to the anarchical structure of the international system. In Arsenal of Democracy, Julian Zelizer subtly aims to upend that belief. He argues that, far from being an incidental factor in foreign policymaking, domestic factors have always been prominent: "Even during the Cold War," that supposed golden era of bipartisanship, "partisan and intra-partisan competition over national security was much stronger than most accounts suggest" (p. 4). From Franklin Roosevelt to Barack Obama, there has rarely, if ever, been a period of national consensus over international affairs, Zelizer claims.

Zelizer, a Princeton political historian, argues that Democrats have oscillated between two foreign policy agendas—one emphasizing the FDR- and Truman-nourished commitment to liberal internationalism, and the other more skeptical toward military intervention after Vietnam. Republicans, meanwhile, have bounced between an isolationism wary of foreign commitment and a large security state, and a unilateral internationalism bordering on militarism (pp. 5–6).

Zelizer is a Democrat who clearly favors the liberal internationalist approach he outlines, but he recognizes that it is not without flaws. Because it prioritizes alliance and diplomacy, a traditional liberal foreign policy is particularly susceptible to demagogic charges of softness and even treason from the right wing. In the book's telling, the midterm elections of 1950 destroyed the Democrats' sense of self-confidence: "The wounds that Republicans inflicted during these elections would not heal for many decades. Psychologists talk about how entire generations can be emotionally scarred as a result of living through war. The story is much the same in these formative years of the Cold War. Democrats would not for decades feel secure with the issue of national security as they had under FDR and, for a while, under Truman" (p. 120). The election also permanently transformed the Republicans: the "GOP, internalizing the arguments of the Republican Right, crossed a threshold in how far it was willing to go in calling Democrats weak on national security and in making partisan use of the issue."

The 1950 election traumatized two Democratic Senators (and eventually Presidents) of particular note: John F. Kennedy and Lyndon Johnson. Both men were terrified of appearing soft on national security, and as a result felt unable to retreat from Vietnam (though Zelizer is clear that Johnson also believed abandoning South Vietnam would be disastrous for national security reasons). The trauma of the Vietnam War, in turn, shell-shocked Democrats into being wary of using force abroad, which further hampered their credibility on national security in the eyes of the electorate.

None of this is exactly new, but never before has anybody laid out so comprehensively the partisan debates over foreign policy. After reading Zelizer's book, it is impossible to believe that a bipartisan foreign policy has ever existed for more than brief, rare periods. Security challenges have always been matters that parties and politicians fought over and sought to leverage electorally. More depressingly, both parties have been persistently willing to put electoral concerns ahead of national security interests. Many Republicans at the time knew Eugene McCarthy was lying but kept quiet because his smears were effective. Similarly, if less ruinously, many Democrats attacked the Bush administration in 2006 for letting operations at major American ports be bought by a Dubai company, even though they understood the acquisition brought no actual threat to national security.

Among the most exciting attributes of Arsenal of Democracy is its grasp of the relevant literature. On everything from Vietnam to Iraq, Zelizer uses the most recent, accurate, respected scholarship. Time and again one jumps to the endnotes to check the source of a novel quotation, only to be impressed with the breadth of research undertaken. Nearly as impressive is the book's even-handedness. Though Zelizer is a liberal, he is critical of liberalism and can be complimentary toward conservatives. The only real exception is Ronald Reagan, who is not given enough credit for bucking his base and recognizing early on that Mikhail Gorbachev was indeed a different type of Soviet leader. The book is highly critical of President George W. Bush (justly, in my view), and sees the present as an opportunity for the Democrats to rebrand themselves as the party that can once again be trusted to secure the country.

The book does not quite answer realism's charge. Zelizer never explores why American voters preferred certain stances— say, zealous anticommunism in 1950—over others. A realist might say that, in a democracy, voters and elites will likely support policies that give their state power and security. Indeed, with the book's thesis being that America's two major parties have always fought over national security credibility, Arsenal of Democracy could be taken as evidence of the power of the international system to influence a state's behavior. I would argue that the anarchical world causes American voters to seek security.

In any case, Zelizer's book is not primarily theoretical, but historical. And as history it is consistently readable and important. It deserves a wide readership. JFQ