In Syria, President Trump is showing a strategic competency that his predecessor most definitely lacked.

Over the past 12 months, Trump has enabled the U.S. military to engage in a more robust and tactically flexible campaign against ISIS. That choice has led to the caliphate’s territorial implosion and its constrained ability to plot external attacks. Yet as ISIS collapses, Syria retains relevance to U.S. national security.

Recognizing as much, on Wednesday, Secretary of State Rex Tillerson pledged that the U.S. will retain a limited military ground presence inside Syria. This presence, the secretary argued, will allow the U.S. to achieve five crucially important strategic objectives:

First, the defeat of ISIS, al Qaeda, and other transnationally-focused terrorist groups.

Second, the establishment of a unified Syria under the leadership of someone other than Bashar Assad.

Third, reduced Iranian influence in Syria so that non-sectarian political empowerment and U.S. regional security interests are protected.

Fourth, the return of displaced peoples to their homes.

Fifth, a Syrian government that is finally disarmed of weapons of mass destruction.

I believe that each of these objectives represents proportionate realism in action. That is to say, these objectives are about ensuring the protection of U.S. interests and basic humanitarian concerns, and not some neoconservative agenda to reshape Syria as a secular democracy.

This realism makes for a refreshing change. Alongside its acquiescence to Chinese and Russian aggression, the Obama administration's greatest foreign policy failure was its 2011 preference of MoveOn.org before U.S. interests in Iraq. Remember, the premature withdrawal from Iraq was the stepping stone that allowed then Iraqi Prime Minister Nouri al-Maliki to turn his nation into a sectarian basket case, leading to ISIS's rise in reaction.

Want to stop new western attacks? Then you should support a retention of forces in Syria. More specifically, keeping U.S. ground forces in Syria ensures that we will have the intelligence, combat and partnership arrangements to defeat any ISIS rebirth and compel Assad's regime to avoid new sectarian slaughters. This latter point is equally crucial in that Assad's targeting of innocent Sunnis and his depopulation campaigns have been a key recruiting agent for terrorist groups.

Similarly, if we care about stopping Iran from destabilizing the Middle East (think car bombs in Beirut, ballistic missiles over Riyadh, assassins in Yemen, sectarian blackmail in Baghdad, and rocket supply convoys that threaten Israel), it is important that the U.S. at least check Iranian influence. Again, this is not about pushing Iran out of Syria, but rather about capping Iranian influence.

Finally, the call for Syria to surrender its chemical weapons represents a much needed dose of deterrent rationality in U.S. policy.

After all, the Obama administration willfully pretended that Assad had surrendered his chemical weapons, and then watched as he drowned Syrian children (that's what Sarin gas does to human lungs). That choice sent the message that the U.S. would tolerate the use of weapons of mass destruction against civilians. In contrast, the Trump administration has drawn a red line and continues to enforce it.

What more could be done?

Well, the Trump administration must also actively deter Turkey and Russia as they threaten our interests in Syria. That said, these five objectives serve our national interests and are worthy of American popular support.