The Middle East has long been a source of misery for Washington. It could be a land of opportunity for Donald Trump.

In his first term as president, Trump brokered diplomatic detentes between Israel and several Arab states. In his second, he¡¯ll encounter a region in which Israeli military successes have dramatically reset the balance of power. That creates the possibility for a bold play to roll back Iran¡¯s influence and curb its nuclear program ¡ª if Trump can avoid stumbling into another Middle Eastern mess.

The regional situation has improved markedly from a year ago, when Israel looked shockingly vulnerable and Iran and its proxies seemed ascendant. Today, Israel hasn¡¯t eliminated Hamas in Gaza, but it has wrecked most of its military capability. In Lebanon, Hezbollah can still fire rockets and conduct ambushes, but its leadership and long-range capabilities have been ravaged by Israeli assaults.