In a tweet last week, U.S. President Donald Trump brought Turkish President Recep Tayyip Erdoğan to his knees.

In early January, when he announced his decision to pull U.S. forces out of Syria, the American president hailed Erdoğan as someone who could fight and even defeat the Islamic State group on his own. Now Trump has decided to take a whack at Erdoğan and put him in his place.

The Turkish president deserved the dressing down he received. Drunk with his success at breaking Washington’s alliance with the Kurds in Syria, he threatened to pummel the Kurds, while other Turkish officials even threatened to “slaughter” them. In the eyes of Ankara, the Kurds are simply terrorists—worse than the Islamic State and Syrian President Bashar Assad—and must be fought.

Trump’s response to Ankara’s brazenness was short to follow, and the president took to Twitter to warn Erdoğan that he would destroy the Turkish economy if the Kurds were harmed. The next day, the Turkish lira lost about 2 percent of its value, and it could keep falling. We can assume the welfare of the Kurds wasn’t the only purpose of Trump’s tweet, and that he was looking for an opportunity to show Erdoğan, not for the first time, “who’s boss.”

Like many statesmen before him, Trump came to the conclusion that Erdogan only understands the language of force. It turns out he was right: In Ankara, Turkish officials quickly lowered the flames. The last time the two leaders clashed, the Turkish president was also the first to blink. Three months ago, Trump imposed economic sanctions on Turkey after Erdoğan refused to release an American priest who had been arrested and jailed there. Within a matter of days, the Turks let the priest go.

Russian President Vladimir Putin has also flogged Erdoğan into submission. Four years ago, the Turks shot down a Russian fighter jet that had entered their airspace. At first, Ankara refused to apologize, but after Putin imposed painful sanctions on Turkish imports, and after Russian tourists stopped flocking to Turkish resorts, Erdoğan quickly backtracked and dispatched a letter of apology to Moscow.

Turkey has also been put over the barrel by Egyptian President Abdel Fatah El-Sisi, who deposed previous president and Erdoğan ally Mohammed Morsi of the Muslim Brotherhood—a kindred movement to Erdoğan’s own ruling party. The Turkish president incessantly lambasted El-Sisi and Egypt, and Cairo responded by severing diplomatic ties with Ankara.

The Egyptians, it appears, put absolutely zero stock in Erdoğan. Last week, Cairo hosted an energy and natural-gas conference to promote cooperation with Mediterranean countries that either have natural gas resources or intend to build pipelines to Europe. Israel was one of the guests of honor, along with delegations from Italy, Greece, Cyprus, Jordan and the Palestinian Authority.

Only the Turks weren’t invited, and the Egyptians took pains to ensure they would also have no part in the project to transfer natural gas from the eastern Mediterranean basin to Europe. The supply route, therefore, will pass through Cyprus, Greece and Italy—not through Turkey, as Erdoğan wanted.

The willingness of Trump, Putin, El-Sisi and others to take swings at Erdoğan is important to note, particularly in light of his reputation in Israel and in Europe as a powerful, even omnipotent, leader. These leaders know that Erdoğan is toothless; that he’s a paper tiger who is strong only against the weak, especially in his own country. And they understand that when he’s challenged and his already struggling economy is threatened with disaster, he submits.

This is an important lesson for all the Turkish sultan’s enemies.