Ninety-six years ago, when President Woodrow Wilson ran for re-election, two notable things happened: 1) His campaign used the slogan "He kept us out of war," and 2) he won.

It has been a long time since any president could seek a second term while making that boast. Looking at recent history, you would conclude not that the Constitution allows the president to make war, but that it requires him to do so. Modern leaders don't brag about keeping us out of war but about getting us in.

Barack Obama reinforces that truth more than any president of our era. He owed his victory in the 2008 Democratic primaries partly to his record of opposing the invasion of Iraq—which Hillary Clinton and John Edwards supported.

"We've had enough of a misguided war in Iraq that never should have been fought—a war that needs to end," he said during the campaign. He proclaimed, "Now is the time to start bringing our troops out of Iraq—immediately." His opponents, Democratic and Republican, portrayed him as gullible and weak. But the voters were willing to elect someone who might be slightly averse to war.

Or, rather, someone they thought might be slightly averse. Either Obama's supporters misread him or he misled them. In any case, he turned out to be very receptive to war. Instead of immediately withdrawing our troops from Iraq, he adhered to the very same departure timetable established by President George W. Bush. Not until the end of 2011 did the last American forces make their exit.

In Afghanistan, Obama actually increased our presence, while setting a distant deadline (2014) for ending our combat role. He has greatly increased the pace of drone missile attacks on targets in Pakistan, and he has made them in Yemen and Somalia.

He launched an air war against the government of Libya, which had neither attacked nor threatened us. If this is an antiwar candidate, what would a pro-war candidate do?

So far, Obama has held his fire on Iran and Syria. But that brings to mind the scene in the movie "City Slickers" when Billy Crystal asks Jack Palance, "Killed anyone today?" Responds Palance, "The day ain't over yet."

Still Republicans are determined to disparage him as a UN-loving, concession-granting, unilaterally disarming appeaser. At least since 1972, they have prospered by painting Democrats as soft on the threat of the day—from communism to militant Islam.

The narrative of this year's GOP campaign will follow the theme of Obama the Wimp. They compare him to Jimmy Carter, who suffered the humiliation of the Iran hostage crisis. Obama, they argue, is rushing out of Afghanistan, letting Iran pursue nuclear weapons, gutting the defense budget and "apologizing for America." He is simply not warlike enough.

The spectacle involving Chinese dissident Chen Guangcheng gave Republicans the chance to shift attention away from the killing of Osama bin Laden to an alleged example of mortifying capitulation. Mitt Romney pronounced it "a day of shame for the Obama administration."

Never mind that U.S. diplomats actually helped Chen reach the sanctuary of the American embassy in Beijing, and that they had no way to prevent Chinese agents from threatening retribution on his family. The particulars of the new controversy don't really matter. What matters is that the default response of American politicians to foreign disputes is breathing fire and belching smoke.

This is partly a cause and partly an effect of a reality that Americans generally manage to overlook. As University of Chicago political scientist John Mearsheimer puts it, "We're addicted to war."

When the Cold War with the Soviet Union ended two decades ago, many people expected to bask in the warm sunshine of lasting peace. The optimism was unwarranted. Every president is a wartime president. Since 1991, notes Mearsheimer, we have been at war in two out of every three years.

Military considerations increasingly shape—and warp—our entire system of democracy and law. Despite the absence of any major threat to our safety and independence, we have become a garrison state, permanently mobilized for incessant intervention. It's a safe bet that whoever wins in November, we will be embroiled in a new war sometime in the next four years.

Romney and Obama may pretend they represent stark differences in America's approach to national security and world affairs. But in this realm, there is no Democratic or Republican party. There is only the war party.

Steve Chapman blogs daily at newsblogs.chicagotribune.com/steve_chapman.