From the beginning of Saudi Arabia’s intervention in Yemen, it was Prince Mohammed’s war.

Prince Mohammed bin Salman, then 29 and in his third month as defense minister, was shown in official photographs surrounded by generals, poring over maps, inspecting a helicopter and even wearing a pilot’s headset while riding in the back of a military transport plane.

Four years later, the war is lodged in a stalemate and Prince Mohammed’s signature fight has become a quagmire, diplomats and analysts say. A steep pullout by his key ally, the United Arab Emirates, they say, raises questions about Saudi Arabia’s ability to lead the war on its own.

Emboldened by the hawkish comments of Trump administration officials, Prince Mohammed is now hoping Washington will help make up the difference with new American military support, according to diplomats with knowledge of the conversations.

But congressional opposition to the war makes that highly unlikely, leaving the prince with some potentially humbling choices.