But they also placed the nation on high alert over concerns of retaliation from Tehran against the U.S. or its allies, including concerns over 40,000 U.S. troops in the region.Start the day smarter.

The US hit three nuclear sites in Iran overnight - but it remains unclear whether the strikes did destroy all of Iran's ...

The world is watching to see whether Tehran responds to the U.S. military strikes as leaders urge Iran to negotiate.