The U.S. Department of Homeland Security warned Americans of a "heightened threat environment" on June 22 that could include attacks on U.S. soil. That fear appeared to dissipate when Iran attacked a United States military base in Qatar June 23, injuring no one.

The Iranian military announced the strike against Al Udeid Air Base. Qatar confirmed the attack and said there were no casualties.

President Donald Trump on Monday announced that Israel and Iran had agreed to a ceasefire, after more than a week of fighting following Israel's strikes -- and subsequent U.S. attacks -- on Iran's nuclear program.