Question

one of the most effective ways governments cooperate to defeat terrorism is by signing treaties. joining in military strikes. creating international agreements. seizing the funds of terrorist organizations.

Explanation:

Terrorism is a global issue. Signing treaties (a more formal and comprehensive form of international agreement) is a key way for governments to cooperate. Military strikes might be a part but are more unilateral or coalition - based in a narrower sense. Creating international agreements is a bit too vague compared to treaties. Seizing funds is an important measure but more of a complementary action. Treaties set out clear, binding obligations among countries for a coordinated approach against terrorism.

Answer:

signing treaties.