Cycle of revenge: What’s next after killing of Iran general?

The unprecedented killing of Iran’s top general in a U.S. airstrike in Iraq has sent shockwaves across the Middle East, with Iran and its allies vowing revenge amid fears of an all-out war. Iran and its allied forces have vast arsenals and are within striking distance of U.S. troops deployed in Syria, Iraq and the Gulf. But they may be wary of launching a retaliatory attack that could ignite a major conflict. The targeted attack itself could give them pause by signaling that the mercurial President Donald Trump is willing to wield U.S. military power in dramatic and unforeseen ways.