No president can anticipate all of the problems that will arise on his “watch,” but surely even his worst enemies will admit that George W. Bush has been handed more than his fair share of exploding cigars.

To be sure, observers have long foreseen that a time would come when an alarming number of medium-sized nations would acquire the ability to construct nuclear weapons and the technology to inflict them on other countries. Hence the decades-long effort to impose restrictions on such efforts, notably through the Nuclear Non-Proliferation Treaty. But the treaty has been only marginally successful, and a series of presidents of both parties have watched a chain of ill-intentioned “rogue nations” move resolutely toward nuclear capability, and simply thanked their stars that the bad actors wouldn’t reach it while they were in the White House.

As luck would have it, the chickens came home to roost during the administration of the junior Bush. North Korea is believed to have succeeded in constructing about half a dozen nuclear weapons, plus missiles capable of dropping them on South Korea, Japan, Alaska and Hawaii. And Iran is thought to be within two or three years (some say less) of developing them, along with missiles that threaten the Middle East and perhaps Europe too. Worse yet, North Korean dictator Kim Jong Il has demonstrated a willingness to sell such weapons to other countries, and quite possibly to terrorist organizations as well.

The result is that, unless the United States and the rest of the world can persuade or compel North Korea and Iran to stop seeking nuclear capability (and, in the case of North Korea, destroy the weapons it already has), we must face the grim prospect of a world in which every important nation, and perhaps various terrorist groups, will, before long, be armed with nuclear bombs. If, heaven forbid, one were detonated in a major American city, we might not even know whom to blame.

As if that were not enough to worry Bush, he had the bad luck to be president on Sept. 11, 2001, when Osama bin Laden uncorked his long-planned attack on the World Trade Center and other targets. Since the Pentagon was almost certainly a secondary target for a hijacked plane that couldn’t find or hit the White House, and United 93 (thanks to its courageous passengers) ended up in a Pennsylvania field rather than knocking the Capitol’s dome askew, we can be grateful that the carnage wasn’t worse. But the attacks signaled the opening of an entire new war against the United States and the Western world in general, waged by anonymous Muslim fanatics all too ready to carry out suicide missions.

Would I be considered unduly kind to Bush if I suggested that he didn’t exactly need Hurricane Katrina?

To Bush’s great credit, he hasn’t crumpled before this ghastly mixture of grisly attacks and unspeakable dangers. On the contrary, he has confronted them stoutly, by a combination of diplomatic and military measures, and shows not the slightest sign of backing down. One may quarrel with his choice of targets or techniques — the Democrats have been strikingly inventive in this regard, if a little short of alternative suggestions — but George W. Bush, however history comes to regard him, is hardly likely to be criticized as a “do-nothing president.”

When he steps down in January 2009, the burden of coping with these problems, whatever form they may by then have taken, will be assumed by his successor. If it is Hillary Clinton — stoutly supported, no doubt, by House Speaker Nancy Pelosi, and perhaps even Senate majority leader Harry Reid — the American people will swiftly learn how good the Democrats are at battling Kim Jong Il, Iranian President Mahmoud Ahmadinejad, and Osama bin Laden, or their successors.

Meanwhile, for two and a half more years, the shots will continue to be called by George W. Bush. May the Lord grant him a steady eye.