How do political parties with different policy-making interests and veto power respond to international terrorism—can coalition parties and bicameral legislatures overcome their policy-making tensions and form a unified front for adopting counterterrorist measures? This study examines German counterterrorist legislation before and after the attacks of 9/11 by using a dictionary-based computerized text analysis. Our findings demonstrate that in times of low threat, the level of intra-coalition and bicameral conflict decreases the likelihood of counterterrorist legislation. However, in the event of a high external threat, this effect disappears despite the continuing divergence in partisan policy preferences. This suggests that a high external threat imposes inaction costs on political parties, which they attempt to avoid by adopting counterterrorist measures in the legislative arena.