Turkey has been a NATO ally since early in the Cold War, but President Obama's decision to embed special forces with the Syrian Kurd militias has put us on a collision course.

Turkey's President Recep Tayyip Erdogan threatens "all necessary measures" to prevent Syrian Kurds from advancing west of the Euphrates River. The People's Protection Units (YPG) of the Democratic Union Party (PYD) is America's principal ally fighting ISIS in Syria. Attacking the YPG puts Turkey and the US on a collision course...
Now, the YPG is pushing west from Jazeera towards Jarabulus. The US recently provided 50 tons of ammunition to the YPG and affiliated Arab fighters, readying for the battle to liberate the ISIS stronghold of Raqqa.

President Erdogan has claimed that the PYD, PKK, and ISIS are all the same thing, despite those groups being locked in a life-or-death struggle.

Last week Turkey admitting that their jets have been bombing Syrian Kurd positions, which shows that Turkey is serious about this pledge.

The Pentagon has admitted that the 30-50 special forces embedded in the YPG will be going on combat missions.
This is after Obama promised 16 times not to put "boots on the ground" in Syria.

So far, the Obama Administration has claimed that those forces are working with a Sunni-Kurdish alliance called the Syrian Democratic Forces (SDF), but reality on the ground is different.

The group didn’t form out of nowhere, of course, and in many ways it didn’t form at all, as the indications are that the Democratic Forces exist in name only, and were largely an invention of the US for branding’s sake after the last failed rebel-creation plan.
The “Arab groups” involved are all but non-existent, meaning the Democratic Forces boil down to the Kurdish People’s Protection Units (YPG), simply relabeled in hopes that the US can start pouring aid into them more rapidly without infuriating Turkey for arming the YPG.

Who are we fighting again?

It may seem complicated and confusing that our NATO ally of Turkey is vowing to bomb our special forces in Syria if they advance against ISIS.
But that isn't the half of it.

For example, Washington's official policy has been regime change in Syria, with active support of Syrian rebels.
In fact, just the other day we sent another $100 million to Syrian opposition, making a total of half a billion dollars. This is despite the fact that most of the armed Syrian opposition are jihadists.

So while we invest immense amounts of money and arms trying to overthrow the Syrian government, guess who is doing more than anyone else to prop up the Syrian government? No, not Russia.

Recent online activities show that various Iranian-backed Iraqi Shiite militias have greatly expanded their recruitment efforts in support of the Assad regime, including numerous reports of significant battlefield action.

That's right. Iraqis, and same ones we are fighting alongside against ISIS in Iraq, are pouring into Syria by the thousands to fight for the same Assad regime that we want to overthrow.
Therefore, who are our allies depends on what side of the border we are standing.
Does this sound like a good situation to send our troops into?

And it gets worse.
One of those Iraqi Shia militias called Turkey Iraq's "biggest enemy".
And then there is this.

The previously unreported move to stop the cash shipments pushed the Iraqi financial system to the brink of crisis and marked a climactic moment in efforts to avert the flow of dollars to U.S. foes.
The situation sheds light on an important facet of the long-running U.S. battle against terror: Just as military officials worry about U.S. weapons getting to enemies, finance officials are on a global hunt to keep dollars from getting into the hands of adversaries who could use it to finance their activities.
The spread of Islamic State set off alarms among U.S. officials about the potential for the currency shipments to be exploited by terrorists.
...
U.S. officials around that time had concerns that Islamic State had gained access to dollars through the auctions, U.S. officials and people familiar with the matter said. The Iraqi officials believe the money has definitely gone to Islamic State through these auctions.
Exchange houses in the northern, Kurdish-controlled city of Kirkuk—outside of Islamic State control but close to extremist front lines—are among the most active in allowing dollar flows into Islamic State-controlled territory and to Islamic State militants, Iraqi officials said.

So we had to cut off money to Iraq, because it was winding up in the hands of ISIS under the nose of our Kurdish allies.
Yeh, sending troops into this sounds like a wonderful idea.