With U.A.E. withdrawal from Yemen, Saudi Crown Prince could lose an ally

What's happening: The Saudi crown prince is increasingly seen as toxic by members of U.S. Congress.

• The war in Yemen, where Saudi Arabia has been fighting Iranian-backed Houthi rebels since 2015, has claimed hundreds of thousands of lives and resulted in the world’s worst ongoing humanitarian disaster.
• Additionally, a recent UN report found "credible evidence" that MBS ordered the murder of journalist Jamal Khashoggi.
• Accordingly, and in a rare bipartisan stand against the Trump administration, the U.S. Congress voted in June to block new arms sales to Saudi Arabia.
• At the G20 summit in Osaka at the end of June, most world leaders gave MBS a wide berth, though President Trump notably praised him for doing "a spectacular job."

Between the lines: If tensions between the U.S. and Iran escalate into full-blown conflict, the U.A.E. could become one of the first targets of Iranian missiles. Pulling forces home means the U.A.E.’s de facto ruler, Crown Prince Mohammad bin Zayad, can better defend his Gulf emirate.

• The move also placates U.S. Congressional critics of the war in Yemen.

What we're watching: Whether the U.A.E. will shift to fighting al Qaeda and ISIS in Yemen, which could also curry favor with American lawmakers, and how their alliance plays out in Libya, where the U.A.E. supports a rebel leader fighting the UN-backed government.

Lawrence Pintak is a professor at Washington State University and the author of "America & Islam: Soundbites, Suicide Bombs and the Road to Donald Trump."