Editorial Board, Wall Street Journal:

The promise of a successful nuclear deal with Iran is that it will stop nuclear proliferation, moderate Tehran’s behavior, make the Middle East a safer place, and perhaps allow the U.S. to play a less active role in a troublesome region. Try telling that to the Arab leaders who were supposed to visit the White House and Camp David this week, but are now finding a reason not to show up.

President Obama announced the visit when he unveiled the Iran “framework” last month. The goal is to reassure the king of Saudi Arabia—along with the emirs and princes of Kuwait, Qatar, Bahrain, Oman and the United Arab Emirates—that the U.S. will continue to support them despite the nuclear deal with Iran. The President has also suggested he’ll have a “tough conversation” about their internal politics, though how another Obama lecture on good governance will ease concerns about U.S. reliability is anyone’s guess.

But at the last minute the senior Arab leaders are finding excuses not to make the trip. New Saudi King Salman pulled out on the weekend only days after confirming his attendance, and he will send lower-level officials instead. Bahrain’s king has also bowed out. These rejections can only be described as political snubs rooted in distrust of President Obama and his diplomacy.

***

The White House will now have to scramble to rescue its policy, and one thing we can expect is a new round of arms sales to the Gulf. The region is already awash in new weapons, including a recent announcement that Qatar will purchase $7 billion in French fighter jets. The signature U.S. contribution will probably be the Terminal High Altitude Area Defense System (Thaad), which can shoot down Scuds and other ballistic missiles fielded by Iran.

More.