THE BURNED OVER DISTRICT

Then proceed to make a mockery of it by engaging in 8 years of constant warfare. Such is the legacy of Barack Obama that was seldom mentioned.

President Obama came into office seven years ago pledging to end the wars of his predecessor, George W. Bush. On May 6, with eight months left before he vacates the White House, Mr. Obama passed a somber, little-noticed milestone: He has now been at war longer than Mr. Bush, or any other American president.

If the United States remains in combat in Afghanistan, Iraq and Syria until the end of Mr. Obama’s term — a near-certainty given the president’s recent announcement that he will send 250 additional Special Operations forces to Syria — he will leave behind an improbable legacy as the only president in American history to serve two complete terms with the nation at war.

Mr. Obama, who won the Nobel Peace Prize in 2009 and spent his years in the White House trying to fulfill the promises he made as an antiwar candidate, would have a longer tour of duty as a wartime president than Franklin D. Roosevelt, Lyndon B. Johnson, Richard M. Nixon or his hero Abraham Lincoln.

Granted, Mr. Obama is leaving far fewer soldiers in harm’s way — at least 4,087 in Iraq and 9,800 in Afghanistan — than the 200,000 troops he inherited from Mr. Bush in the two countries. But Mr. Obama has also approved strikes against terrorist groups in Libya, Pakistan, Somalia and Yemen, for a total of seven countries where his administration has taken military action.

“No president wants to be a war president,” said Eliot A. Cohen, a military historian at Johns Hopkins University who backed the war in Iraq and whose son served there twice. “Obama thinks of war as an instrument he has to use very reluctantly. But we’re waging these long, rather strange wars. We’re killing lots of people. We’re taking casualties.”

Mr. Obama has wrestled with this immutable reality from his first year in the White House, when he went for a walk among the tombstones at Arlington National Cemetery before giving the order to send 30,000 additional troops into Afghanistan.

His closest advisers say he has relied so heavily on limited covert operations and drone strikes because he is mindful of the dangers of escalation and has long been skeptical that American military interventions work.

Publicly, Mr. Obama acknowledged early on the contradiction between his campaign message and the realities of governing. When he accepted the Nobel in December 2009, he declared that humanity needed to reconcile “two seemingly irreconcilable truths — that war is sometimes necessary, and war at some level is an expression of human folly.”

The president has tried to reconcile these truths by approaching his wars in narrow terms, as a chronic but manageable security challenge rather than as an all-consuming national campaign, in the tradition of World War II or, to a lesser degree, Vietnam. The longevity of his war record, military historians say, also reflects the changing definition of war.

President Obama is certainly not as careless with military lives as W and Darth Cheney but he does love to blow up other countries. Does this indicate a bloodthirsty streak in him or is he just unable to resist a man with lots of medals and brass? Either way he has left a legacy that would be unwelcome to follow.