"I think I screwed up." - President Barack Obama on the Daschle nomination.

The crash-and-burn of Tom Daschle's nomination to head the Health and Human Services Department wasn't the first bad news to hit the new administration. Nor will it be the last.

Many in the media depicted Daschle's fall from grace as a disaster for the president. But this episode is really no more than an unsettling blip. It reveals little about how President Obama will handle the great challenges of the day.

Presidential mettle can only be measured by serious trials that test character and leadership. President Obama will face plenty of real challenges over the next four years, and we'll know them when we see them. Odds are they'll start arriving faster than he wants -- or expects.

The White House has tried to look like it's moving fast on many problem areas. In less than two weeks Obama had: announced plans to close Guantanamo Bay and other terrorist detention facilities; vowed to solve global warming, and appointed czars for global problems ranging from cyber threats to Middle East conflicts.

Yet the administration has shown little interest in actually driving the world agenda. In the real hot spots -- like Iraq, Afghanistan, and Pakistan -- Obama's policies look an awful lot like Bush policies. Elsewhere, the administration has signaled only an interest in "dialogue" -- the diplomatic equivalent of "let's do lunch."

This is understandable. Like all presidents, Obama wants to focus on his domestic agenda for the "first hundred days." But passive global leadership cedes the initiative to others, and some of those "others" are more than happy to drive the agenda in ways that can create real crises.

No issue carries greater potential for crisis than the growing threat of missile attack. Last week, Iran launched its first homemade satellite into space. Foreign Ministry spokesman Hassan Qashqavi assured an alarmed world that "Iran's space advancement serves no military purpose."

He is probably right... today. But Americans should be worried today, for the same reason they worried when the Soviets launched Sputnik in 1957: the launch demonstrates the increasing sophistication of a hostile nation's ballistic missile program.

Layer that on top of Iran's rapidly progressing nuclear program (which they also claim has no military purpose), and you have to wonder when Iran will drop the other shoe -- a "surprise" test of its first nuclear weapon.

North Korea hasn't been quiet either. Pyongyang has just abrogated a bunch of agreements with the South, and media reports indicate a new long-range missile site is 80 percent complete, with another round of missile tests imminent.

It may be only saber-rattling intended to cow the leaders in Seoul. With Kim Jong-Il, you never know...And that's the problem.

Also troubling, though, are the administration's early signals on missile defense. It said nothing when Sen. Carl Levin, D-MI, declared, "We are going to cut weapons systems" and singled out the missile-defense program.

Also worrisome, some of the newbies have suggested they might try to make nice with the Russians by reneging on our commitment to build missile defenses in Europe.

The surest way for the administration to set itself up for a colossal crisis is to abandon missile defense. To do so in the face of provocative actions by tinhorn tyrants in Iran and North Korea -- or in response to mere complaints from Russia -- is to look weak and inept. And that would invite disaster.

To paraphrase Lt. Gen. Henry "Trey" Obering, the recently retired director of the Missile Defense Agency: "When all else fails -- when all the negotiations have broken down -- you must be able to destroy a missile in the air. Otherwise, all you can do is apologize to those who died."

In matters of life-and-death import, like missile defense, "I screwed up" won't cut it.

James Jay Carafano is a senior fellow at The Heritage Foundation and the author of GI Ingenuity: Improvisation, Technology and Winning World War II.