This post has been updated.

The news doesn’t look promising for President Obama’s summit Thursday with heads of the six Persian Gulf states. The meeting is to offer security assurances to our grumpy Arab allies that a possible nukes deal between the United States and their bitter enemy, Iran,would not disadvantage them.

But Saudi Arabia’s King Salman, the most important of the six heads of state,  backed out Sunday — even after telling Secretary of State John F. Kerry last week  he would be there — claiming he had to deal with a brief cease-fire in Yemen. (Seriously.)

It appears right now that only two of the six gulf nations’ rulers — the emirs of Kuwait and Qatar — will be in attendance.

Some observers thought the drop in attendance was the result of unhappiness with Obama and deep concerns that an agreement with Iran would only cause that country to be even more belligerent.

However, a source close to the Saudi government told our colleagues Carol Morello and Karen DeYoung that the Saudis “did not mean it as a snub” to the administration. And administration officials also said no snub was intended.

We have another theory about why some leaders are suddenly coming down with the vapors and can’t attend: Maybe it’s the location.

Sure, Camp David is lovely, peaceful, suitable for serious talks. It’s on 120 acres in Catoctin Mountain Park only about a half-hour chopper ride from Washington. But its dozen of lodges — named after trees — are perhaps a tad rustic for this crowd of potentates, who would seem much more comfortable at maybe the Four Seasons on Hawaii’s Big Island or perhaps the Burj al-Arab in the United Arab Emirates.

While President Bush II enjoyed going to Camp David, Obama has not gone there much. So the guests might wonder why they are going to a place he doesn’t like.

More importantly, there are ghosts to exorcise. After all, Camp David was the site of some seriously polarizing negotiations between Israel’s Menachim Begin and Egypt’s Anwar Sadat in 1978, and between Ehud Barak and Yasser Arafat in 2000.

Selecting the right lodge can be problematic. Who wants to stay in the Dogwood Lodge, where Sadat stayed before he was assassinated a few years later? (Bad Karma there.) And who wants to stay in the Birch Lodge, where Begin stayed?

Also, what if they come under attack? Obama has a fine elevator in his bedroom closet in the Aspen lodge that goes right down to a huge, deep underground bunker, as author Lawrence Wright recounted in his fantastic book, “Thirteen Days in September.” Everyone else, well….