US President Donald Trump is again breaking diplomatic norms in backing Israel's capture of the Golan Heights, with experts warning that he risks justifying expansionism by other countries.
Israel conquered the Golan from Syria in the Six-Day War of 1967 and annexed it in 1981, but until now, the international community has not accepted the move, hoping the territory could serve as a bargaining chip in a future peace deal between the countries.
But Trump on Thursday turned to Twitter for the abrupt diplomatic turnaround, saying that after 52 years, "it is time for the United States to fully recognize" Israeli sovereignty.
The move - which came as Trump's ally, Prime Minister Benjamin Netanyahu, faces elections - has caused dismay even among US allies, with Britain and France both saying they still considered the Golan Heights to be "occupied" by Israel.
Richard Haass, president of the Council on Foreign Relations, feared the consequences of walking away from UN Security Council Resolution 242, which stressed the "inadmissibility of the acquisition of territory by war." The measure was passed after the Six-Day War.
"This is the most fundamental principle of international order and was the basis of US opposition to Saddam's conquest of Kuwait and Putin's of Crimea," Haas said, referring to the 1991 Gulf War in which a US-led coalition freed Kuwait and Russia's 2014 seizure of the Ukrainian peninsula.
It is not the first time that the real-estate mogul turned president has brazenly dismissed international conventions. In December 2017, Trump recognized passionately contested Jerusalem as Israel's capital, fulfilling a major goal for the Jewish state.
In a television interview Secretary of State Mike Pompeo rejected the suggestion that the United States was using a double standard by recognizing Israeli sovereignty in the Golan while imposing sanctions on Russia for annexing Crimea.
"What the president did with the Golan Heights is recognize the reality on the ground and the security situation necessary for the protection of the Israeli state. It's that simple," he told Sky News.
Pompeo characterized the US as a "force for good" in the region, with "noble" intentions.
"We want good outcomes... for all nations in the Middle East, and the decision the president made will increase the opportunity for there to be stability throughout the region," he said.
Sweden's former foreign minister Carl Bildt said that Trump was returning to the law of the "jungle."
"This is a catastrophic departure from the very basis of international law. Kremlin will applaud and apply the same principle to Crimea. Beijing will applaud and apply to South China Sea," Bildt tweeted.
Syria and its ally Iran reliably denounced Trump's move. Turkish President Recep Tayyip Erdogan - fearful of a breakup of Syria under which Kurds could seek independence - said that Trump has created a "new crisis" and called for intervention by the Organization of the Islamic Conference.
But allies also worried about the implications. France's foreign ministry said in a statement that recognizing Israeli sovereignty "would be contrary to international law, in particular the obligation for states not to recognize an illegal situation."
Steven Cook, an expert on the Middle East at the Council on Foreign Relations, questioned the need to shake up the status quo, saying that US recognition only triggered fresh opposition to Israel's longstanding control of the Golan, where 20,000 settlers live.
"In reality, there is no need for the recognition. Israel is in Golan for its own reasons, and nothing the Trump administration decides will change that," he wrote in an article in Foreign Policy magazine.
Ilan Goldenberg of the Center for a New American Security said that Trump's decision "stirs a hornet's nest that didn't need stirring."
"Also, it makes it quite hard for the US to continue to contest Russia's annexation of Crimea under the principle that taking territory by force is illegal. We now have no leg to stand on and the Russians will use it," he tweeted.
"So why do it? Because this is awesome for Bibi's politics," he said, using Netanyahu's nickname.