By Doyle Mcmanus

Richard C. Holbrooke, who died last week at 69, was most often described in terms of his larger-than-life style. He had protean energy, bulldozer tenacity, and an always visible ego, all of which he used in relentless pursuit of what he felt was America's duty: to try to fix the world's problems.

But the last time I had a conversation with Holbrooke, he sounded frustrated.

"How does this thing end? I don't know," he said last summer, talking about the overwhelming obstacles America faces in Afghanistan and Pakistan. "It is really the toughest thing that I've ever attempted."

And that, for Holbrooke, was no small admission.

He began his diplomatic service in Vietnam, a tragic failure of American foreign policy. But instead of concluding, as others did, that the United States should do less, he concluded that it should get better at using its power. He devoted much of his life to trying to show his fellow Democrats that American power could be wielded unapologetically and effectively.

He saw Americans go through several bouts of "declinism" - the view that U.S. power was bound to wane - but he refused to believe it.

In 2008, before the presidential election but with the economy already in trouble, he wrote: "The next president will inherit leadership of a nation that is still the most powerful in the world ... that could, and must, again inspire, mobilize and lead the world. His core challenge will be nothing less than to re-create a sense of national purpose and strength after a period of drift, decline, and disastrous mistakes."

As a practitioner of diplomacy, Holbrooke proceeded from that combination of purpose and bravado. He constantly urged action, not hesitation, prompting more cautious diplomats to describe him as a bull in a china shop.

His willingness to threaten as well as promise, and to negotiate with villains, helped him achieve his greatest triumph, the 1995 peace agreement that ended the war in Bosnia-Herzegovina. He later called Yugoslav President Slobodan Milosevic a "monster," but added, "Sometimes you have to negotiate with murderers."

On what he presciently called his "last mission" - as President Obama's special envoy to Afghanistan and Pakistan - Holbrooke never got a chance to try his negotiating skills on the Taliban. He was in favor of negotiations with the insurgents; if a path toward ending the war opened, he said, the United States should be "opportunistic." But no such negotiations were in view, so Holbrooke focused on turning the prickly U.S. relationship with Pakistan - Afghanistan's neighbor and the Taliban's refuge - into a stable strategic alliance.

Indeed, one of his main contributions to the Obama administration's policy was his insistence that the most important country in that part of the world wasn't Afghanistan, with 30 million people, but Pakistan, with 180 million and nuclear weapons. He helped coin the term AfPak to describe the two countries as a single problem, then switched to PakAf to correct the priority. (Eventually, after Pakistanis said they disliked being lumped in with their smaller, more backward neighbor, he dropped both.)

Another Holbrooke contribution was his vigorous insistence that the United States should stop spending time and money on an unpopular and unsuccessful campaign to eradicate Afghanistan's opium-poppy crop - a recommendation that was radical at the time but is now largely embraced as common sense.

But much of his job turned out to be a long, unglamorous series of bureaucratic battles to get U.S. aid and advisers flowing into Afghanistan and Pakistan to win hearts and minds, just as had been tried in Vietnam.

And he was frustrated, friends said, both by the intractability of the problems he was trying to solve and by his limited influence in the Obama administration. He was close to Secretary of State Hillary Clinton but was the object of thinly veiled criticism from the White House, which suspected he talked to the media too much.

Holbrooke wasn't a dove; he was a realist. He believed the United States needed to lower its sights in Afghanistan and find an outcome that was achievable at a reasonable cost. But he still believed we needed to remain involved in Afghanistan and Pakistan for years to come.

It was characteristic that he was still talking about the problem even as he was taken to the emergency surgery from which he never recovered. "You've got to relax," one member of his medical team told him, according to State Department spokesman P.J. Crowley. "I can't relax," Holbrooke replied. "I'm worried about Afghanistan and Pakistan."

Doyle McManus is a Los Angeles Times columnist.

He can be reached at doyle.mcmanus@latimes.com.