“We are fighting against terrorists in northern Syria and we will continue it until they will be eradicated,” Erdogan said during a commemoration of the 569th anniversary of the Ottoman conquest of Istanbul.

Erdogan is, to put it mildly, an Ottoman nostalgist, so his choice of that particular venue to announce a possible new invasion of Syria was significant.

“The conquest of Istanbul took place as a result of genius plans, tremendous efforts, masterful preparations, unprecedented sacrifices, and an unwavering perseverance and determination,” Erdogan gushed during his tribute to Turkey’s imperial history.

Erdogan told reporters aboard his plane on Saturday that a new attack on Kurdish forces in Syria would come without further warning.

“Like I always say, we’ll come down on them suddenly one night. And we must,” he said.

The Kurdish militias Erdogan is targeting are part of the People’s Protection Units (YPG), the Syrian Kurdish force that was allied with the Western world during its war against the Islamic State.

Erdogan considers the YPG to be indistinguishable from the Kurdistan Workers’ Party (PKK), a terrorist group that has been fighting an insurgent campaign against Turkey for decades. On Saturday, he repeated his long-standing complaints about the U.S. and Europe supporting YPG units against ISIS.

“All coalition forces, leading with the U.S., have provided these terror groups a serious amount of weapons, vehicles, tools, ammunition and they continue to do so. The U.S. has given them thousands of trucks,” he said.

“Just as we are conducting operations in northern Iraq against the PKK and PKK’s offspring, the same situation applies even more to Syria and is much more important,” he said. Turkey launched a new air and ground offensive against Iraqi Kurdish fighters in April.

“If the U.S. is not fulfilling its duty in combating terror, what will we do? We will take care of ourselves,” he warned.

Turkey’s fourth incursion into Syria, dubbed “Operation Peace Spring,” was launched in 2019 and never truly ended, as Turkey still occupies positions on Syrian territory. Turkey was roundly condemned for invading Syria and attacking the YPG, including stern criticism from Turkey’s nominal allies in the North Atlantic Treaty Organization (NATO).

In return, Erdogan has been threatening to block Finland and Sweden from joining NATO. On Saturday, the Turkish president repeated his accusations that both of those countries “support terrorism” because they are allegedly harboring PKK militants.

Erdogan claims his goal in Syria is to create a “safe zone” or “buffer” along the Turkish border that would prevent Kurdish militants from threatening Turkey. The Jerusalem Post last week accused Erdogan of plotting another invasion to pump up his poll numbers, and denounced Turkey’s campaign as “ethnic cleansing,” noting it has pushed a tidal wave of 200,000 Kurdish refugees deeper into Syria.