Beyond War Powers: Patterns of legislative assertiveness in US Congress

In order to explain under which conditions US Congress asserts itself in the politics of military interven-tions previous studies focused on the role of the president’s party power, divided government, casualties or public opinion. The literature primarily relied on a traditional concept of war powers focusing on ex-ante authorization ignoring non-material elements such as public critique, oversight, parliamentary dis-courses or non-binding legislation. In contrast, this paper uses a more nuanced understanding of congres-sional powers and highlights the construction of security interests in conjunction with public opinion and casualties to make sense of congressional assertiveness as well as deference. Through a mixed-method approach combining fuzzy-set QCA and discourse analysis, the paper argues that congressional assertive-ness is connected to cases in which MoC perceive no security interests and where the public disapproves of the intervention. On the other hand, Congress is mute in cases where security interests seem to be involved even though casualties mount. The results indicate that factors such as public opinion and casual-ties need to be seen in conjunction with the construction of security interests influenced by MoC.