President Barack Obama makes a statement in the White House...

President Barack Obama makes a statement in the White House on Thursday, April 23, 2015, about a U.S. drone strike that targeted a suspected al-Qaida compound in Pakistan, but inadvertently killed an American and Italian being held hostage by the group. Credit: Mark Wilson

On Tuesday, President Barack Obama lost a vote on trade policy in the Senate. The strange thing is why he lost. For years, conservatives have voiced impatience with Obama's foreign policy. But this time, all but one Republican voted for him, and all but one Democrat voted against him.

Foreign policy used to be one of Obama's political strengths. But since June, his ratings have hovered around 40 percent. With so many Democrats opposing his signature initiative, a lot of liberals are joining conservatives in moving on -- in different directions -- from Obama.

But moving on to where? To know where to go, it helps to understand where you've been. There's no better guide than "The Obama Doctrine: American Grand Strategy Today," a new book by Colin Dueck, a professor at George Mason University.

Obama's starting point, Dueck argues, is that he cares most of all about domestic policy. Obama doesn't want to change the world: he wants to transform the United States. His goal is to avoid being Lyndon Johnson, who tried to build his Great Society but instead was consumed by Vietnam.

But no president can ignore foreign policy. In dealing with it, Obama's been tactically flexible. He's not, for example, been willing to take the political hit of closing Guantanamo. If you define a strategy as a coherent plan, Obama doesn't have one.

But he does have guiding assumptions. Obama's strategy -- his doctrine -- is to retrench abroad by accommodating adversaries so he can focus on the United States.

Retrenchment means withdrawing from Iraq and Afghanistan. It means cutting U.S. military spending, even if we need a bigger navy to make the pivot to Asia a reality. It means relying on words -- like Obama's infamous "red line" in Syria -- to do the work of deeds. And if pushed into intervening, as Obama was in Libya in 2011, it means not having a plan for the aftermath.

Accommodation isn't diplomacy, which negotiates agreements that offer something for everyone. Accommodation means giving the other side what it wants, in the hope that this will change their behavior so they cause us fewer problems.

Hence, we've had the Russian reset, "normalization" with Cuba (which conceded much to the Castros in return for very little), and, now, the Iranian nuclear deal, which would leave Tehran's program intact and make re-imposition of sanctions all but impossible.

Obama's not interested in the United Nations, a traditional liberal fetish. He wants a legacy, and in domestic policy, he's got it, in the form of Obamacare. But abroad, his legacy is the Russian invasion of Ukraine and beheadings in Syria.

The results of the Obama experiment have been disappointing. He's left no enduring success. Hence the push on trade: it's Obama's last chance to make a lasting impression.

That's the final irony of Obama's strategy. Since 1945, expanding trade has been central to U.S. leadership in foreign policy. Of course, U.S. trade deals need to be done right: free trade can't be a cover for European-style corporatism.

But many on the left now see expanding trade as a bad thing: they're even less interested in foreign policy than Obama. Conservatives, meanwhile, are pulling the opposite way, toward the defense of our allies, diplomacy that's not a giveaway, and international leadership.

The battle is under way: On Thursday, the president won another Senate vote on trade, with the majority of his party continuing to oppose him, and Republicans egging him on. Obama's doctrine hasn't worked abroad. And now, it's not commanding support at home either."