Saudi Arabia’s window to exit the conflict in Yemen without jeopardizing all of its gains is quickly closing, as the United States transitions to a less Riyadh-friendly government, and as Houthi rebels seek deeper concessions on the ground. On Nov. 17, Saudi Arabia reportedly offered the Houthis a buffer zone along the Saudi-Yemeni border in exchange for drawing down its forces in the country. This move marks a significant downgrade to the original Saudi objectives in the country, as well as a tacit acknowledgment of the likely longevity of the Houthi political and military presence in Yemen. ...