Trump vows 'America first' foreign policy and no Middle East nation-building

Republican White House hopeful Donald Trump promised on Wednesday a overhaul of US foreign policy to put "America first", make its allies pay up and abandon Middle East nation-building.

In a speech short on specifics that left Washington policy experts scratching their heads, Trump said: "Our foreign policy is a complete disaster," dismissing all presidents serving since the Cold War, both Republicans and Democrats.

David Sanger of the New York Times noted that Trump said the US would do no nation-building, but that it would build stability around the world. “Hard to know how you do one without the other,” Sanger wrote.

Many were quick to point out contradictions in a strategy of restoring US strength and crushing the Islamic State (IS) group while cutting allies loose.

"We're rebuilding other countries while weakening our own," he said, decrying nation-building missions in the Middle East and the US trade deficit with China.

Trump was clear on where he sees the greatest threat to the US, accusing Democratic frontrunner Hillary Clinton of a refusal to name it.

"Containing the spread of radical Islam must be a major foreign policy goal of the United States and, indeed, the world," he said.

Interventions, Middle East chaos

Anne Barnard of the New York Times, however, noted that Trump lumped in Syria with Iraq and Libya as arrogant interventions that have led to chaos in the Middle East.

But US involvement in Syria has been much more hands off, she wrote, with President Barack Obama refusing deeper involvement despite the urging of allies like France, Saudi Arabia and Turkey, rivals like John McCain and even prominent members of his own State Department.

Trump vowed to re-tool Nato to oppose "radical Islam" and migration and put US national interests ahead of all other considerations.

"'America first' will be the major and overriding theme of my administration," he said, co-opting the slogan of America's pre-World War II isolationists.

"Our allies are not paying their fair share," he said, pointing the finger at both Nato and close Asian allies such as Japan and South Korea. 

"The countries we are defending must pay for the cost of this defence. And if not, the US must be prepared to let these countries defend themselves. 

Despite this, he quickly pivoted to an attack on Obama, accusing him of abandoning US allies like Israel while reaching out to Iran.

Obama and Israel, Iran

"We picked fights with our oldest friends and now they're starting to look elsewhere for help. Remember that. Not good," Trump said.

Trump has been widely mocked for failing to secure big name, foreign policy endorsements and relying on a coterie of right-wing fringe figures.

But he defended his team, slamming the available talent in Washington circles as tainted by the chaos unleashed under former President George W Bush.

But many experts noted that Trump was announced at the podium by one of Bush's closest advisors on the Middle East, Zalmay Khalilzad, former ambassador to the UN, Afghanistan and Iraq.