When the French and the British carved up the Middle East, the Golan Heights was part of the French mandate. It was not part of the Palestinian territories, where the Israelis claimed their authority. And after the mandate was abolished for the current nation-states, the Golan Heights was naturally left for Syria.
U.S. President Donald Trump took yet another step to legitimize Israeli expansionism after recognizing Jerusalem as Israel's capital last year. 'After 52 years it is time for the United States to fully recognize Israel's sovereignty over the Golan Heights, which is of critical strategic and security importance to the state of Israel and regional stability', Trump tweeted. Governments around the world reacted harshly to that decision.