From time to time, states will choose to directly and explicitly link economic cooperation to security cooperation. How effective is this strategy?
My doctoral dissertation shed new empirical insights into how economic cooperation enhances security cooperation. I showed that economic cooperation bolsters the credibility of an alliance commitment and showed that offers of economic cooperation could secure military cooperation in the first place. Besides contributing to the literature on the political economy of alliances, this research also brought new insights into how we understand ``issue linkage''. Issue linkage is when states decide to include two or more unrelated issues in a single agreement. Issue linkage has commonly been viewed as a mechanism by which states can achieve "cooperation under anarchy." The logic is that including multiple issues in a single agreement -- thereby providing "something for everyone'' -- makes all the parties willing to sign on and adhere to an agreement. Though the concept of ``issue linkage’’ has a long literature, its effectiveness lacked empirical support. This is why the dissertation was titled "Issue Linkages and International Cooperation: An Empirical Evaluation"
The first half of the dissertation sought to determine if linking issues raised the probability of agreement substantially (perhaps by 25 percentage points), marginally (perhaps by 1 percentage point), or not at all. I used the inclusion of trade cooperation provisions in military alliance treaties as a means of gaining empirical leverage on this question, as trade cooperation and military cooperation are two issues that are clearly separable (meaning states can and have negotiated agreements on just trade, or on just alliances). I collected new data on failed alliance treaty negotiations and identified whether those negotiations witnessed trade cooperation offers. After combining my data on failed negotiations with existing data on when states have formed alliance treaties, I used matching techniques to estimate that offers of issue linkage raised the probability of agreement by over 30 percentage points.
The second half of the dissertation sought to determine if linking issues enhanced the credibility of and compliance with treaty obligations. I did this by focusing on the alliance relations of buffer states. Buffer states are states located between two recently or currently warring rivals, such as Poland during the 1920s and 1930s. The alliance relations of buffer states create a "hard case" for treaty compliance. This is because buffer states are especially prone to invasion and occupation, thereby making other states reluctant to remain committed to an alliance agreement with the buffer state. Hence, if economic linkage provisions can enhance the credibility of alliance commitments for buffer states, then linkage provisions should improve treaty compliance in nearly any context. I find that buffer states in alliances with trade provisions experience fewer opportunistic violations of the alliance terms, avoid occupation and invasion at a higher rate, and experience fewer third party attacks than buffer states in other alliance arrangements.
The dissertation was published as a series of papers, including in International Organization and the Journal of Conflict Resolution, and received the 2012 Walter Isard Best Dissertation Prize from the Peace Science Society. The policy implications of this research are highlighted here.
I built on this resarch by exploring a particular episode of trade and alliance linkages inflluencing conflict dynamics: the American Civil War. In a piece published in Security Studies, I argue that the Abraham Lincoln authorize the use of militarized force against the Conferdate states in order to dissuade the Europeans from recognizing and aligning with the Confederacy. This was a notable decision since Lincoln initially promised not to use force against the Confederate states. But Lincoln and his cabinet feared that European dependence on southern cotton would incentivize them to support the Confederacy.
In addition to offering a powerful historical example of trade-alliance linkages (except one in which such linkages failed to form), this paper offers a new narrative on the Civil War's onset. While it is well recognized by historians that concerns over European recognition influenced Union behavior throughout the war (from the Trent Affair, to the issuance of the Emancipation Proclamation), scholars have not fully considered that fear of recognition might have influenced events at the war's beginning. This paper was reviewed here and inspired a co-authored piece in the American Journal of Political Science looking at leader decisions to use force after promising to refrain from using force.