Defense Secretary Mark Esper says that in talks with NATO nations later this week, he will urge those nations to contribute more to the US deployment in Saudi Arabia, including paying more for the thousands of US troops there.
Though this appears to be chiefly about money, Esper also suggested NATO members should send ships and warplanes to the region to support Saudi Arabia. The US deployment is chiefly about threatening Iran.
It’s not clear on what basis the US could demand NATO involvement, as nether defending Saudi Arabia nor threatening Iran are anything to do with the NATO treaty’s intentions, and the whole situation is far afield of the North Atlantic.
An even bigger question that’s sure to be asked is whether the US actually intends to turn a profit on this venture. President Trump is already claiming that Saudi Arabia is paying the cost in full of the deployment of US troops, so it’s absurd to also suggest NATO nations pay the US as well.