Frida Ghitis

The political phenomenon of the summer has defied all predictions and still leads the Republican primary polls. So, as the rest of the world continues rubbing its eyes at America's political spectacle, it may not be too soon to try to discern how a President Trump would conduct his foreign policy.

What would Commander-in-chief Trump do about ISIS, about Russia's intervention in Ukraine, about the rise of China, about Iran?

The question will gain urgency if Trump's lead holds up. In the latest Iowa poll, Ben Carson has vaulted into a tie with Trump at the top of the GOP field. Still, Trump's support amounts to only about one in four Republicans. Capturing the White House still looks extremely unlikely.

But if he does, a Trump presidency is sure to bring to the world stage strong words, hard bargaining and, by all indications, a muscular and unconventional foreign policy.

Trump's speeches and interviews have provided flashes, glimpses into his thoughts on how America should respond to individual crises, but nothing like a coherent worldview that could tell us what a Trump Doctrine for America's place in the world would look like.

That may be because he did not expect to find himself in this position and didn't spend a lot of time developing a cogent philosophy. Trump likely has surprised himself with his surge in the polls.

A look at his campaign website shows a barren landscape on the issues. The only subject under "Positions," is -- you guessed it -- "Immigration Reform." And you won't be surprised at the heading: "Immigration Reform that Will Make America Great Again."

Beyond the wall?

People are well acquainted with the proposals: a wall along the border between Mexico and the United States, a pledge to make the Mexican government pay the costs to build it, and a vow to stop giving U.S. citizenship automatically to all babies born in the United States. That pledge stands in direct contradiction to the prevailing understanding of the 14th Amendment to the Constitution, which would make changing the rules a steep uphill climb. And it's hard to see how Mexico could be persuaded to pay for a wall certain to ignite controversy.

But what about the other pressing challenges of our turbulent world?

As president, Trump would be not only commander-in-chief but top foreign policy strategist and premier diplomat. After all, nobody exercises more influence on U.S. foreign policy than the man in the Oval Office. His policies would most likely contain statements mixing bursts of common sense and out-of-the-box policy proposals.

That is not to say he would have an unfettered hand. Once in office, the diplomatic, political and military establishment would exert some influence, as would the Congress. And Trump would presumably surround himself with experienced professionals. Still, he would have the last word, and it is a safe bet that he would extend little patience to aides who consistently challenged his ideas, as his many displays of thin skin suggest

Take Iraq's oil?

Trump has already shown a pattern of mixing doses of common sense analysis with hard-to-fathom policy ideas, and hyperbole devoid of policy content.

On the rise of ISIS, for example, Trump told Anderson Cooper that the war in Syria and Iraq "is not our fight. That's other people's fight." But ISIS is so brutal that, "Nobody will be tougher on ISIS than Donald Trump."

What he would do is "Bomb the hell" out of the Iraqi oil fields that support ISIS. "You take away their wealth ... take back the oil." That would include the use of American ground troops in the battlefields where ISIS fights.

Trump has suggested taking the oil from Iraq to finance better services for American war veterans. "We're going to have so much money!" he boasted.

That's the kind of strategy that might work on a board game. In the real world it's barely conceivable. Destroying Iraq's oil infrastructure would be a disaster. And then stealing its oil? Even if the military could pinpoint the ISIS-controlled oil fields, the damage could prove devastating to Iraq's fragile economy.

The outgoing Army Chief of Staff Ray Odierno, who has considerable experience with Iraq, said he disagreed with Trump -- who would probably respond, "You're fired."

Risky stance on China

On the rise of China, Trump proposes imposing import tariffs on Chinese goods, the starting salvo in what could quickly become an old-fashioned trade war. "They want our people to starve," he said of the Chinese, drenching the proposal in typically undiplomatic slander.

The idea of tariffs may please some in the United States, but history has shown that trade wars are ultimately disastrous for all sides. Most economists agree, for example, that imposing sharp tariffs was one of the grave errors, in fact, one of the causes, of the Great Depression.

On Russia, Trump is optimistic. "I think I would get along very well with Vladimir Putin." Maybe so. One writer, David Ignatius, called Trump "the American Putin," noting that, like the Russian President, the American tycoon "seems to understand that power and showmanship are inseparable."

The two might get along, but that would likely do nothing to resolve strategic disagreements between Russia and the United States on subjects such as Putin's intervention in Ukraine. When Trump told Fox's Bill O'Reilly that he would have a "great relationship with Putin," O'Reilly shot back, "Based on what? You're two macho guys?" Trump responded with a nonsensical stream of chatter about making deals and references to George W. Bush's I.Q.

On Iran, Trump has sharply criticized the nuclear deal as unacceptable. "I think it's going to lead to nuclear holocaust," he said on "Meet the Press." And yet, unlike other GOP candidates, he now says he will "police" the deal, not rip it up.

Either way, he promises, "very, very forceful action."

The overarching theme is that above all, and in contrast with Obama, he would be a tough and skilled negotiator for America. He is, by the way, not the first to criticize the Obama administration for its poor negotiating skills.

Carson says he's studying the issues

The latest polls show another unlikely Republican hopeful closing in on Trump. The retired neurosurgeon Ben Carson is threatening to topple Trump from the lead in Iowa, which raises previously inconsequential questions about Carson's foreign policy.

Carson's campaign website offers more than Trump's, but not a lot of details. On Russia, it says, "All options should remain on the table when dealing with international bullies such as President Putin." On ISIS, Carson says "We have to eradicate them now," and has declared he would be prepared to put American boots on the ground to do it.

Carson admits that foreign policy is not his strong suit, saying he is studying the issues, "There's a lot of material to learn."

That's one point where he diverges from Trump: Few people have heard Trump say he has a lot to learn about any subject. That's true about foreign policy, where Trump speaks with characteristic verbal swagger even though his professional experience is in, well, real estate.

When you close your eyes and imagine foreign policy under President Trump, you see American diplomats, U.S. allies, and enemies all nervously bracing for the unexpected.

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