When Turkish warplanes bombed fighters from the People’s Protection Units, or YPG, in northeast Syria on the morning of April 25, embedded U.S. special...

When Turkish warplanes bombed fighters from the People’s Protection Units, or YPG, in northeast Syria on the morning of April 25, embedded U.S. special forces were “uncomfortably close” to the targeted area, according to a YPG source cited by Al-Monitor.

Specifically, U.S. troops were only a few miles away.

“There was less than an hour of notification time before the strikes were conducted,” said U.S. Air Force Col. John Dorrian, a spokesman for the U.S. campaign against Islamic State. “That’s not enough time and this was notification, certainly, not coordination as you would expect from a partner and an ally in the fight against ISIS.”

Dorrian added that U.S. troops could not effectively react given the the vague and rushed nature of the warning.

In the aftermath of the Turkish strike, U.S. Army fighting vehicles flying the Stars and Stripes drove to the Syrian-Turkish border to deter clashes between Turkey and the YPG—the largest element of the U.S.-backed Syrian Democratic Forces.

Turkish threats to target the YPG have continued. On May 3, Turkish President Recep Tayyip Erdogan’s chief adviser on Kurdish affairs, Ilnur Cevik, even went so far as to declare that:

“If they [the YPG] go too far, our [forces won’t care] that American armored vehicles are there … Unexpectedly, a number of rockets may also hit them by accident.”

“If they [the United States] do this [work with the YPG], what are you supposed to do,” he added, later walking the statement back but only partially.

Boots meet ground. Footage of American special forces and their Stryker ICVs rolling around Al-Hasakah, northeastern #Syria. pic.twitter.com/6aYyCzHOIX — Haidar Sumeri (@IraqiSecurity) May 1, 2017

Erdogan doubled down on his vow to continuously hit the YPG. “As I said yesterday, ‘we may come there at night without warning.’ I meant this,” he said on April 30. “We do not announce [our plans] beforehand, giving dates to terrorist organizations. They know that the Turkish military could come there at any moment.”

“They live in fear, not us.”

While Turkish fire did not harm any U.S. troops, five Kurdish soldiers in Iraq were not so lucky. The Turkish Air Force accidentally killed them when trying to target PKK fighters in Iraq’s Sinjar region that very same day.

If Ankara continues to hit the YPG in Syria in such a haphazard and unilateral fashion then the chances of killing more friendly forces is bound to increase. Even with coordination there is always a risk of friendly-fire incidents in close quarters, recently evidenced by the United States’ own accidental bombing and killing of 18 SDF fighters in mid-April.

The prior deployment of U.S. Army Rangers to the SDF-controlled city of Manbij in early March also served as a deterrent to Ankara’s plan to attack that city. After all, Turkish air or artillery bombardments there would run the grave risk of killing American soldiers.

A U.S. military officer with YPG and YPG officers after Turkish air strikes in Hasakah, Syria. VoA capture

Incidentally, Washington and Moscow play similar arbitration roles in Syria.

Russia supports the Syrian regime and has sought to prevent intermittent clashes between loyalist troops and the Kurds in Syria’s northeast from escalating. Moscow is on good terms with both sides and therefore opposes a full-blown confrontation between them.

Same goes for the United States and Turkey, both long-time allies and members of NATO. It is therefore not in U.S. interests to see a war break out between Turkey and the YPG, America’s main ally against Islamic State. Consequently, the U.S. government has sought to encourage deescalation between the two sides anytime they clash.

But what would actually happen if Turkish fire directed at the YPG actually killed American soldiers in Syria?

Two past attacks on American warships provide a possible answer to this question.

In May 1987, Iraqi Super Etendard strike fighters attacked the frigate USS Stark in the Persian Gulf killing 37 sailors. U.S. Pres. Ronald Reagan, then aiding Iraq in its war against Iran, accepted Iraqi dictator Saddam Hussein’s claim that it was unintentional.

Cooler heads prevailed.

“We’ve never considered them [the Iraqis] hostile at all,” Reagan said after the incident. “They’ve never been in any way hostile. And this was at night, of course, so [they] never had any visual sight of the target. They fired by radar that missile.”

The burning frigate USS ‘Stark’ after an Iraqi Exocet missile attack in May 1987. U.S. Navy photo

Twenty years earlier during the June 1967 Arab-Israeli War, Israeli warplanes attacked the USS Liberty spy ship in the Mediterranean, killing 34 crew members. Israel maintains that it had misidentified the Liberty as an Egyptian ship.

The carriers USS America and Saratoga scrambled warplanes, but soon recalled them on direct orders from the Pentagon. The U.S. ambassador in Cairo later said he received a warning that an attack was imminent, as the White House apparently believed Egypt was initially responsible. But accounts vary, with other reports indicating that the Sixth Fleet assumed Soviet forces carried out the attack.

In any case, the immediate confusion following the Liberty incident serves as an apt warning of the dangers of Washington misidentifying any possible Turkish attack on their troops for a Syrian or Russian one.

In August 2016, Syrian warplanes targeted Kurdish forces in the northeastern city of Hasakah—amid clashes between them and pro-regime militiamen. The bombs landed near a group of U.S. special forces. U.S. Air Force F-22 Raptors were subsequently scrambled to the area to prevent the Syrians from carrying out any follow-up attacks.

If those strikes even inadvertently killed American troops, the United States may well have responded swiftly and forcefully, especially under the incumbent administration. And were another Turkish attack—carried out without proper coordination and warning—to kill U.S. servicemen, a misunderstanding could see U.S. planes retaliate against the wrong target.

Following the U.S. cruise missile strike on the Al Shayrat Air Base on April 6, Syrian military aircraft reportedly relocated near Russia’s main air base in Syria for protection. This increases the risk that such a U.S. retaliation against Syrian forces could end up hitting and killing Russians as well.

The U.S. military has already heavily criticized Ankara’s strike while the White House’s has remained relatively silent on the matter, ahead of Erdogan’s upcoming visit. The United States needs to make it clear to Turkey that future strikes without following the correct coordination procedures could lead to a disastrous outcome.