In the midst of ongoing criticism of President Trump's decision to pull out U.S. troops from northern Syria, including by many conservative allies, President Trump has earned rare praise, from both allies and critics, for the elimination of the Islamic State's leader, Abu Bakr al-Baghdadi.  While the elimination of al-Baghdadi bolsters U.S. deterrence and is a keystone national security accomplishment, such deterrence can be best maintained in the long term by ensuring the safety of the Kurdish-led SDF (Syrian Democratic Forces) in northern Syria, particularly in the face of the threat from Turkey.  Most importantly, ensuring the safety of Kurdish forces can be accomplished even without U.S. boots on the ground.

President Trump's historic victory in the all-important battle against the forces of evil through the elimination of al-Baghdadi is certain to be remembered, especially as a prime achievement that strengthens U.S. deterrence against those who seek to harm the U.S. and its allies.  President Trump, and certainly the U.S. Special Forces, involved in the mission, deserve unanimous praise for the monumental victory in the battle between good and evil.  And while the Islamic State terrorist organization is not completely defeated — and the U.S. must remain vigilant as to the threat from ISIS and others that would seek to harm the U.S. and our allies — the victory against ISIS leadership and territorial control is an important component in maintaining U.S. deterrence against emergence of other threats.

Probably an even greater national security achievement than the demise of al-Baghdadi was the defeat of the Islamic State caliphate by the U.S.-backed SDF (led by the Kurdish YPG) in concert with U.S. forces this past March.  The Kurds have proven to be a consistent and critically important ally who lost an estimated 11,000 fighters in the defeat of the Islamic State with the help of the U.S.  The Kurdish involvement in this critical battle toward the demise of a national security nightmare that was the Islamic State meant that the U.S. suffered very few casualties, certainly relative to a head-on attack against ISIS without SDF assistance.  This is nothing short of a monumental national security achievement.

In fact, since 2014, the total number of U.S. military personnel killed in action (KIA) in Operation Inherent Resolve in the fight against the Islamic State in Syria and Iraq was 17.  Though any number of deaths is tragic, it is eclipsed by the deaths suffered by the SDF and by the 3,481 U.S. military deaths in Operation Iraqi Freedom.  The defeat of the Islamic State caliphate at such a relatively low cost to the U.S. military is a military achievement of historic proportions.

From a strategic perspective, it is therefore of great importance that the safety of those SDF fighters is ensured, with the help of the U.S.  This is particularly important in light of reports of violations by Turkey of the U.S.-backed ceasefire between Turkish and Kurdish forces.  Worryingly, President ErdoДџan admitted that Turkey's military campaign is focused on attacking the "PKK/YPG," lumping U.S. ally YPG (People's Protection Units) together with the Kurdish PKK.  This, notwithstanding that it was the Kurdish YPG that helped beat back the Islamic State in the first place.  Even more disturbing is President ErdoДџan's threat to "cleanse" the area of northern Syria that Turkey would control of these Kurdish forces if they do not leave the area by the end of the ceasefire.  In effect, Turkey threatens to kill a large number of Kurdish allies — those same soldiers who fought to realize the demise of the Islamic State's caliphate — unless all of those whom ErdoДџan defines as Kurdish fighters leave the "safe zone" in northern Syria.

Paradoxically, it is President ErdoДџan who time and again not only lists the YPG as part of the same organization as the Kurdish PKK, but lumps the YPG together with Daesh (i.e., the Islamic State) as "terrorist organizations."  Even in his congratulations to President Trump for bringing about the demise of the head of ISIS, President ErdoДџan made sure to list the YPG as a terrorist organization, fighting on the side of terrorism, rather than being the spearhead in the very fight against ISIS.

Instead, it is Turkey's military operation in Syria that has led to the escape of at least about 950 ISIS supporters from Kurdish prisons and may make it much more likely that more of the estimated 11,000 ISIS terrorists and 70,000 ISIS supporters will be able to escape.  On October 23, State Department special envoy on Syria James Jeffery confirmed that the whereabouts of over 100 escaped ISIS fighters are still unknown.

It is increasingly clear that notwithstanding the importance to the U.S. that ISIS fighters not be permitted to escape, Turkey is in fact responsible for helping ISIS terrorists escape prison by attacking the Kurds, rather than only weakening them.  And while the SDF has proven to be a consistent ally against ISIS, Turkey has also proven its two-faced approach to ISIS.  While Turkey has sporadically attacked ISIS forces in retaliation for attacks on Turkey, Turkey also purchased oil smuggled in by ISIS.  Turkey's history with ISIS has demonstrated that Turkey is an unreliable partner in the war on the Islamic State.

The manner in which President Trump proceeds with respect to SDF allies in northern Syria will send a message to friend and foe alike.  President Trump's actions to defend Kurdish allies will send a message of deterrence to foes and a message of reliability to allies.  Continued support of the Syrian Kurds will be in line with President Reagan's doctrine of peace through strength.  While having a strong military is one component of peace through strength, demonstrating the willingness to use that strength when consistent with U.S. national security needs is the other component, without which deterrence is substantially limited.

With the exclusion of U.S. forces protecting key oilfields, President Trump can effectively defend Kurdish allies and further U.S. national security goals without U.S. forces on the ground in northern Syria.  This can be achieved using four means at his disposal:

1. President Trump should immediately impose a no-fly zone over Kurdish territory in northern Syria — as requested by SDF allies.  It should be understood by all parties that U.S. air power would be brought to bear in defense of Kurdish allies.
2. President Trump should immediately provide the SDF with vast quantities of all types of advanced conventional weaponry that could benefit them.
3. The U.S. should also immediately issue an ultimatum to Turkey that it immediately and permanently cease attacks on the SDF forces in northern Syria or face full sanctions — free of any waivers. 
4. Finally, the U.S. should sign a mutual defense treaty with SDF Kurdish allies in northern Syria.

In light of the timeliness and importance of defending SDF allies, President Trump must act immediately and effectively to preserve gains made in the fight against the Islamic State and to protect the SDF from any renewed Turkish air and ground attack.  Immediate action would also preserve strategic alliances with allies around the world, particularly Israel and Saudi Arabia, who are increasingly threatened by an Iranian regime bent on their destruction and the destruction of the United States, and on becoming a nuclear power in possession of nuclear-tipped missiles.

Especially when the U.S. has ISIS on its heels, it is in the vital national security interest for the United States to protect and preserve the SDF in order to prevent a re-emergence of the Islamic State, protect critically important alliances elsewhere, and demonstrate to friend and foe alike that the United States is a reliable ally in time of need.  It will also significantly bolster U.S. deterrence, making it that much less likely that U.S. forces will need to be used as often to further U.S. national security in line with President Reagan's doctrine of peace through strength.