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?
Trump said that ISIS was defeated. Also, the US sold A 3.5 billion dollar patriot missile system to Turkey. US abandoned the Kurds. ISIS prisoners were released or broke out of jail. Terrorist attacks are still a concern and not only for Israel.