Which factor contributed to tensions in the U.S.-Iran relationship after 2015?

Which factor contributed to tensions in the U.S.-Iran relationship after 2015?

• A. Iran's Leadership Change.
• B. Iran's Missile Program and Regional Behavior.
• C. NATO Expansion.
• D. Joint Actions With North Korea.

Answer: (B)

The key factor is Iran’s missile program and its regional behavior. After 2015, tensions with the United States grew not mainly from a change in Iran’s leadership, but from Tehran’s ongoing development and testing of ballistic missiles and its active role in regional conflicts. Iran expanded its influence through support for proxies and militias across the Middle East (in places like Syria, Iraq, and Yemen), which the U.S. and its allies viewed as a destabilizing challenge to regional security and to the limits discussed in nuclear talks. The JCPOA of 2015 did constrain Iran’s nuclear activities but did not curb missiles or regional behavior, so those elements kept driving friction. The other options don’t fit as well: there wasn’t a leadership overhaul in that period, NATO expansion is unrelated to Iran, and North Korea ties weren’t a central driver of U.S.–Iran tensions.

The key factor is Iran’s missile program and its regional behavior. After 2015, tensions with the United States grew not mainly from a change in Iran’s leadership, but from Tehran’s ongoing development and testing of ballistic missiles and its active role in regional conflicts. Iran expanded its influence through support for proxies and militias across the Middle East (in places like Syria, Iraq, and Yemen), which the U.S. and its allies viewed as a destabilizing challenge to regional security and to the limits discussed in nuclear talks. The JCPOA of 2015 did constrain Iran’s nuclear activities but did not curb missiles or regional behavior, so those elements kept driving friction. The other options don’t fit as well: there wasn’t a leadership overhaul in that period, NATO expansion is unrelated to Iran, and North Korea ties weren’t a central driver of U.S.–Iran tensions.