LAUSR

ABSTRACT This article explores whether party polarisation in the American Congress affects the length of legislated sanctions. While Congress can enact sanctions, it usually authorises the president to waive, suspend or terminate them. However, Congress can prevent the president from ending a sanction if both parties can cooperate to block the presidential proposal or pass a sanction bill challenging the presidential preference. Borrowing from moderate polarisation argument that both parties can cooperate only when they are moderately polarised, I argue that the probability of sanction termination declines if Congress is moderately polarised but increases when Congress is either least or extremely polarised. This is because only under moderately polarised Congress can both parties cooperate to stop the sanction termination. I test this argument using TIES data (1945–2005) and find support for this expectation. This research contributes to our knowledge on the role of congressional dynamics in shaping American foreign policy.