[katiedidit1]

American troops have been in Syria since 2015, but the latest casualties highlight what has been a consistent, but often quiet, U.S. counterterrorism mission, aimed at countering Iranian-backed militias and preventing the resurgence of the Islamic State group. Iran is another reason the U.S. remains in Syria
Tehran’s political influence and militia strength throughout the region have created a security concern for the U.S. Since the defeat of the Islamic State group, Iran-backed fighters have expanded their influence in the region.

The presence of American forces in Syria makes it more difficult for Iran to move weapons into Lebanon, for use by its proxies, including the Lebanese Hezbollah, against Israel. source Military Times

[Jim Noble]

"Tehran’s political influence and militia strength throughout the region have created a security concern for the U.S"..."The presence of American forces in Syria makes it more difficult for Iran to move weapons into Lebanon, for use by its proxies, including the Lebanese Hezbollah, against Israel"

I understand this is an Israel problem. It is a security concern for the United States only because we have troops illegally in Syria, vulnerable to attack. Had President Trump's orders been followed and those troops returned home, what other US security concerns are you worried about?