By Mark Egan
NEW YORK (Reuters) - Call it the Trump Doctrine. The next time America is called upon to act as global policeman, expect a bill from Uncle Sam.
Property developer, reality TV star and would-be Republican presidential candidate Donald Trump says he'd apply his business acumen to geopolitics if he wins the White House.
A cultural phenomenon known as "The Donald," Trump is leveraging his reputation as a showy business mogul to set up a possible run for president.
Some of Trump's proposals fall way outside the political mainstream. But his message that America needs radical change draws support from some voters dismayed by diminished economic prospects at home and growing challenges to U.S. power abroad.
On Tuesday, he jointly topped a poll of would-be Republican hopefuls in the nascent 2012 White House race.
For many Americans, Trump is the larger-than-life property mogul who ends each U.S. episode of the TV show "The Apprentice" with the catch phrase "You're fired." On foreign policy issues, Trump is just as blunt.
Under a President Trump, China would be forced to end currency manipulation or face a 25 percent tariff on all exports to the United States. OPEC oil-producing nations would have to drop the price of a barrel or oil to $40-50 or face America's wrath. And Arab nations and South Korea would pay for benefiting from America's military might.
He singled out the recent trade pact with South Korea, signed after a military showdown with communist-ruled North Korea, saying it was a "joke" with insufficient benefits for the United States.
"We go over there, we protect them, we protect them with our ships ... Did anyone pay us for this? No! So, what is happening is mind-boggling."
Trump also took aim at the Organization of the Petroleum Exporting Countries.
"OPEC will cut the price of oil, and if they don't they've got problems," he said. "We are protecting Saudi Arabia free of charge. The Arab League asked us to go into Libya and we go in and we don't say, 'Are you going to pay for it?'"
"I would tell (OPEC) that oil is not going to $150 a barrel
... it's going to be at $40-50 a barrel."
On China, Trump accused Beijing of manipulating its yuan currency, contributing to a U.S. trade deficit that was unacceptable -- it was $18.8 billion in February alone.
"I would put a 25 percent tax on all goods coming in from China to the United States and I would do it without hesitation," Trump said.
THE GREAT FALL OF CHINA?
Economists concerned about the U.S. trade deficit with China say upsetting Beijing could prompt the Chinese to buy less U.S. debt, which in turn would increase U.S. interest rates and make credit here more expensive.
Trump sees it as global test of wills.
"If we stop buying from China, China will go down like no other country has ever gone down before," he said. "China needs us more than we need them."
A CNN/Opinion Research Corporation survey released on Tuesday showed Trump and former Arkansas Governor Mike Huckabee led a poll of would-be presidential contenders with 19 percent each -- a doubling of Trump's support since mid-March.
Trump has been on a media blitz for weeks, claiming that U.S. President Barack Obama was not born in America and therefore cannot legally hold the presidency -- an allegation that has been widely dismissed.
"I do find it amazing how the media protects Obama on his birth certificate," Trump offered without prompting.
As to how much he would spend on his campaign, the man who ranks 488th on Forbes magazine's 2010 list of the world's billionaires with an estimated net worth of $2 billion said, "A lot ... whatever is necessary."
He said he would consider running for president as an independent but wants to win the Republican nomination, saying he loves the party. He said he would decide on whether to make a run before June.
Asked if his multiple marriages, bankrupt casinos, roller coaster career and wealth, being a billionaire, a celebrity and regular tabloid fodder would hurt his prospects among ordinary Americans, Trump said times have changed.
"Look, I don't drink, I don't smoke, I don't take drugs. I've had two marriages that ended in divorce, that was nobody's fault. I am a very hard worker and it is very hard to be married to a very hard worker, but I think that's what the people of this country need -- a hard worker."
"Ten years ago it would have been a problem but I think today people want someone who is going to protect them and cherish them and take care of them and work to make this country great again," he said.
(Corrects paragraph 19 to make clear Trump claiming Obama was not born in America and therefore cannot legally be president)