To find out what was going on, Al-Monitor reached a source close to the YPG. This source, who did not want to be named, confirmed that the jets and helicopters were patrolling above them. “Actually, I can see the helicopters now as we are talking,” he said.

After the Turkish airstrikes, the sounds of airplanes were suddenly heard above the region the Kurds call Rojava . The sounds went on for a long time without a break. People in the region at first thought the Turkish planes were back, but a bit later helicopters started to fly over the area — the reality began to emerge later. The planes and helicopters belonged to the anti-Islamic State (IS) international coalition. They crisscrossed the region for several hours, giving the impression of a de facto protection zone. Shortly afterward, action began on the ground. Armored vehicles flying US flags began patrolling the Turkish border. A heavy US armored presence was seen in areas close to Turkey’s key deployment points.

The target in Syria was the YPG command headquarters. The YPG said 20 of its militants were killed. The air attacks were followed by small-scale skirmishes on the border. Neither the Kurds nor the allies were expecting such an attack from Turkey. But the real surprise came a few hours later.

Turkey has consistently warned that it could intervene militarily in the region. But the prevailing view was that Turkey refrained from military action so as not to confront the United States and Russia. That restraint ended April 25 when Turkish jets bombed YPG facilities at Mount Karachok , near the Syrian town of Derik, and Kurdistan Workers Party (PKK) targets near Iraq’s Sinjar.

DIYARBAKIR, Turkey — Developments in northern Syria, which has a large Kurdish population, have long been on Turkey’s agenda. Turkey considers the growing power of the Kurdish Democratic Union Party (PYD) and the People’s Protection Units (YPG) in the region seriously disturbing.

Abdul Karim Omer, co-chair of the Foreign Relations Council of the Jazeera Canton (unofficially the foreign minister), also confirmed the patrol flights by coalition airplanes. Omer told Al-Monitor the United States had to defend the region. “We don’t have an agreed arrangement between us. There is nothing official, but today some coalition commanders came and checked this area, especially at Dirbesiye bombed by the Turks,” he said.

“They moved around with their tanks and vehicles and deployed their tanks at the border. They came to Karachok also. Their visit has political significance. Clearly, they are upset with what Turkey did. There is no official no-fly zone, but they are here. Their tanks are on a road very close to the Turkish border. They expressed their displeasure. We are not happy with the situation. We are fighting terror against an organization threatening the world, and Turks come and attack us. The coalition cannot remain silent on this. But airstrikes could not have taken place without US knowledge. The United States doesn’t want to upset Turkey.”

Nasreddin Ibrahim — secretary-general of the Syrian Kurdistan Democratic Party, which doesn’t identify with the PKK — also observed the coalition overflights. He told Al-Monitor, “American planes showed up after Turkey’s attacks at Karachok and Sinjar and flew between the Iraqi border and Kobani. On the ground, their tanks were moving around in the three areas, flying their flags. One of their units was moving in the area between Kobani and Serekani. Another was between Serekani and Grespi, and the third was between Serekani and Andiwar on the Iraqi border — all close to the Turkish border.

"East of the Euphrates River until the Iraqi border is the US zone of domination. There is a partnership between the United States and the Syrian Democratic Forces [SDF]. The YPG is the main SDF force. Then, there are the Russians in the west of the Euphrates. These two superpowers are protecting Rojava — Russia the west of Euphrates, and the Americans east of the Euphrates. They have forces in three cantons. They now have airfields where their big planes can land. They must now set up official safe zones. Turkish and regime planes must be banned from entering these zones. It must be an official ban. Last year, there were clashes between the YPG and the Syrian regime. If the United States had not intervened, the regime would have leveled this region.”

Academic Mehmet Alkis, who follows the region and the Kurds closely, said the Kurds are the new US allies in the region. Alkis told Al-Monitor that the United States' establishment of a base in the Kurdish region is the best proof of this alliance. “Turkey doesn’t want the YPG or the PYD as dominant powers in Syria’s Kurdistan region," he said. "Turkey sees both organizations as part of the PKK and doesn’t want them to develop into a threat against Turkey. This is Turkey’s red line. For the United States and Russia, it is important for the YPG to continue with its fight against Daesh [IS]. This is why they want to conduct the Raqqa operation with the Kurds. Turkey doesn’t want the YPG to achieve a permanent, recognized status. Turkey also doesn’t want Sinjar to become a military base because it is afraid of it turning into a second Qandil.”

He noted that the presence of American soldiers at the Turkish border means they don’t want Turkey to get involved. Turkey, meanwhile, is trying to improve its hand by diplomatic bargaining with the United States and Russia. “That won’t be easy because the United States wants to find a new actor in the Middle East — and that will be the Kurds, as seen by intensive work to set up US military bases and airfields. Turkey’s policy doesn’t have its previous cachet, while Ankara wants to preserve its political and economic interests by improving ties with the United States,” he said.

Air patrols have ceased for the time being, but armored units flying US and Russian flags are showing up along the Turkish border — American flags east of the Euphrates and Russian flags west of it.

Just as the situation was cooling off, Turkey’s presidential adviser, Ilnur Cevik, triggered a new argument when he said, “If they push it further, our troops may not care about Americans anymore. … Suddenly, by accident, a few rockets may well hit them.”

But everyone knows these words have relevance to the ground. People wonder how such a statement might affect the forthcoming meeting between US President Donald Trump and Turkish President Recep Tayyip Erdogan.

What is happening now resembles the days when the Kurdish autonomous region was being set up after the first Gulf War. The region emerged with US support despite Turkey’s fervent opposition. Today, we also have Russia on the stage. Both the United States and Russia clearly are not going to give up on the Kurds. The most likely scenario will be for Turkey to modify its policies accordingly. We are likely to see frequent photographs of Kurds waving to armored vehicles flying the US flag.