Trump's sudden Syria decision undermines his own foreign policy team

Trump reportedly agreed to the withdrawal during a phone call with Turkish President Erdogan, and at Erdogan's suggestion. This is not the first time Trump has engaged in such sudden decision-making over the strong concerns of his own team.

• Earlier this year, he changed the penalties applied to Chinese company ZTE, after a direct request from Xi Jinping.
• At his Singapore summit with Kim Jong-un, Trump agreed to suspend joint military exercises on the Korean peninsula after Kim asked him to do so.

Why it matters: Few countries will want to negotiate with officials from the White House or the State Department if they know they can get a better deal from the boss himself. This may be one reason Pyongyang has refused working-level negotiations over its nuclear program and instead focused on holding a new, leader-level summit. The temptations of personalizing diplomacy at the head-of-state level are great, but it persuades allies and adversaries alike to bypass the very officials hoping to execute the president's foreign policy agenda.

The bottom line: Successful foreign policy requires the president to fully empower a team that speaks for him. If Trump continues to make on-the-spot course reversals, he will make it more difficult for his administration as a whole to achieve its goals.

Richard Fontaine is the president of the Center for a New American Security.