President Trump's U-turn on withdrawing U.S. forces from Syria probably has more to do with Israeli wishes than anything else. It's no secret that the Netanyahu regime wants U.S. forces to stay in Syria, and National Security Advisor Bolton's announcement about the withdrawal being delayed (indefinitely) came shortly after he'd met with Israeli officials.
It's not that hard to figure out. As long as U.S. troops are in Syria they'll be killing and maiming Arabs, most of whom have no love for Israel no matter which faction they belong to. Once the Islamic State and Al-Nusra jihadis are effectively defeated, then the U.S. forces can focus on what Netanyahu's hawkish bunch thinks should be their main mission -- bringing down the government of Bashar al-Assad. Circumstances might well develop that would also give the U.S. an excuse to attack Iran, a country that worries Israel even more than Syria does.
President Trump's initial decision to withdraw was the right one. America is now $22 trillion in debt and we've already wasted way too many lives in the Middle East. Let the Israelis fight their own battles, which they're well-equipped to do with all the billions of military aid Washington has given them over the decades.