What is Iran’s ‘Axis of Resistance,’ and Which Groups Are Involved?

Houthi supporters attend a rally in support of the Palestinians in the Gaza Strip and against the U.S.-led airstrikes on Yemen, in Sanaa, Yemen, Jan. 26, 2024.

Groups backed by Iran have been waging attacks on Israeli and U.S. targets since war erupted between its Palestinian ally Hamas and Israel on October 7, a campaign that prompted U.S. counterstrikes and fueled fears of a wider escalation.