President Trump prefers to use targeted economic weapons instead of the U.S. military forces against foreign adversaries.  In keeping with this strategy President Trump is announcing a set of economic sanctions and tariffs against Turkey for their decision to cross into Syria and create a crisis amid all regional interests.  (Source)

One of the reasons this strategy is better than any military action is simply because Turkey is a unique NATO ally, and the NATO alliance within Europe is insufferably incapable of taking action to defend their interests.
European NATO members want the benefits of a perpetual U.S. military presence.  That EU outlook is simply beyond the limits of what President Trump is willing to do.  President Trump wants to bring our troops home.
You’ll notice the complete lack of action by the EU that would serve as a deterrent to President Erdogan of Turkey.  All of the responsibility for counter-measures is being placed on the shoulder of Americans and the American taxpayer.  The EU has not, is not and will not, lift a finger to impede the hostile activity by Turkey in Northern Syria.

Ultimately President Trump is highlighting the reason why the U.S. should withdraw from NATO by spotlighting the insufferable weakness of the assembly. NATO won’t even vote to defend their own interests, so why should the U.S. be their crutch?
With Europe refusing to stand-up to defend their own interests, President Trump is removing U.S. forces from the untenable position of guarding all the big cat cages, ad infinitum, to keep the zoo status intact.
Instead, President Trump is going to support the Arab coalition and the GCC that has been assembling a military coalition to protect itself from the Muslim Brotherhood.
That is why President Trump is willing to support Saudi Arabia with more troops, while withdrawing from Syria where the U.S. was having to stand alone to protect the interests of Europeans who will not protect themselves.
In one regional area the U.S. will support and defend Israel, Egypt and Jordan. In the Southern region the U.S. will support the Gulf Cooperation Council (Saudi Arabia, Kuwait, Oman, Yemen, Bahrain and Qatar).
Will political Islam likely have a resurgence in the region, and will Recep Erdogan rise as the head of the Ottoman Empire once again? The former is likely, the latter is unknown.
President Trump is correctly withdrawing U.S. troops from a position of adversarialism against a NATO member. Why should the U.S. protect the interests of allies who will not stand-up to protect themselves…
President Trump is correct.
President Trump will use economic weapons against Turkey…. And, in keeping with the doctrine, Europe better watch out.  President Trump will likely use economic weapons against the EU for creating this mess and refusing to defend themselves.
President Trump will use military weapons to protect allies that are: (A) willing to protect themselves, and (B) willing to pay for the support of the U.S. military protection.
It is really a common sense doctrine… Help those who help themselves.
These two tweets below really are the nub of it; and stunningly transparent.  President Trump is letting it be well known that Turkey is on their own with this decision.  Any entity who wants to assist Syria in defending the Kurds, and or repelling Turkey, is free to do so.

President Trump is leaving President Erdogan naked to his enemies.
There are many consequences possible.

• The EU votes to kick Turkey out of NATO.
• The U.S. leaves NATO because the EU has shown a lack of resolve.
• Turkey gets hammered by Syria, Russia, Kurds, and/or any faction that opposes President Recep Erdogan.
• The U.S-Arab alliance will not be unhappy to see Turkey under fire due to Erdogan’s alliance with extreme political Islam, The Muslim Brotherhood.

This is one of those weird “be careful what you wish for” scenarios for President Erdogan, because in his lust to recreate the Ottoman Empire he just might get removed.