The world thunderously opposes the North Korean a-bomb blast, vowing decisive action. Or does it?

No matter what the answer to the above question, there's no doubt the world is watching to see what President Obama will do. So far, the signs are not encouraging.

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This is a test for President Obama. He says that North Korea must disarm, and he says that Iran must disarm. But what if they don't want to?

The mainstream media is doing its best to paint a rosy scenario of a post-George W. Bush world, falling into line behind Barack Obama's leadership.

The headlinein The Washington Post is both blunt and encouraging: "North Korea Nuclear Blast Draws Global Condemnation/China, Russia Decry Ally." The Post goes on to quote the Chinese as saying that they are "resolutely opposed" to such tests.

So on Monday, Obama issued astern-sounding declaration:

"The danger posed by North Korea's threatening activities warrants action by the international community. We have been and will continue working with our allies and partners in the Six-Party Talks as well as other members of the U.N. Security Council in the days ahead."

Yes, those are good words, but it's worth noting that Obama's policy is indistinguishable from Bush's policy--and that's what got us to where the North Koreans figure they can set off nukes, and fire missiles, with impunity.

Thus the question: Is any of this anti-North Korean action real? Will it change the behavior of North Korea? The answer, sadly, is probably not. By Tuesday, the White House agenda had already changed: The new line was securing the Supreme Court confirmation of Judge Sonia Sotomayor.

Yes, the United Nations Security Council can meet and resolve something, but it's not apparent that one member of the Security Council, China, is in fact "resolutely opposed" to what North Korea just did. And it is readily apparent that China would oppose any sort of preemptive strike on North Korea's nuclear or missile facilities, to say nothing of "regime change."

It's worth remembering that obnoxious as the North Korean regime might be to us, the Pyongyang regime is not so obnoxious to their fellow communists next door, in the People's Republic of China. Yes, China has changed, but the two countries fought a war together, back in the 50s, against Uncle Sam. To many Americans, lamentably, the Korean War, 1950-1953, is "the forgotten war"--even if 36,940 Americans died in the conflict. But the historically minded Chinese remember that they lost on the order of 900,000 men in that conflict. So there's a martial fraternity between the two countries, sealed in blood. Meanwhile, the rest of the world doesn't seem to mind seeing more non-Western countries getting nukes, as a way, perhaps, of balancing planetary power.

Thus the North Koreans are confident in the hand they are playing. Sure, their people might starve in the wake of some new round of sanctions, but they have demonstrated that they don't really care about their people. What they do care about is being international big shots, and that they are.

And of course, on the other side of the world, the Iranians are watching closely. "If Kim Jong Il can have nuclear weapons," Mahmoud Ahmadinejad must be saying to himself, "then why can't I?"

Let's face it: Right now, the calculus in favor of having nuclear weapons is a lot stronger than the calculus against.

In today's world, if the big powers decide they don't like you, you can be removed from power. That's what happened to Slobodan Milosevic, ex-president of Serbia. He got crosswise with the European Union in the 90s, and the next thing he knew, he was in an International Court jail cell in The Hague, where he died in 2006. And that same year, 2006, saw the hanging, in Baghdad, of Saddam Hussein. Saddam, of course, tried to fool the rest of the world into thinking he had weapons of mass destruction. That bluff was punctured by the U.S. in 2003, and look where he ended up.

The lesson to dictators and tyrants is clear. If you don't have nukes, or some other kind of weapon of mass destruction, you can be picked off. But if you do have nuclear weapons, well, it's a whole different story. Look at Pakistan. Everyone walks on eggshells when discussing that country and its 80-100 nukes. -- So, the leader of Pakistan is a respected figure, whom the world seeks to ply with more foreign aid.

This is a test for President Obama. He says that North Korea must disarm, and he says that Iran must disarm. But what if they don't want to?

For better or worse, the sword of regime-change is back in its scabbard. Yes, finally, the surge worked to calm things down, but the Iraqis still want us to leave, after we lost more than 4,000 lives and spent a trillion dollars.

And on a political level, the Republicans took a beating because of the war. The GOP lost its Congressional majority in 2006, and its pro-war, pro-surge presidential candidate, John McCain, lost decisively in 2008.

Moreover, today America is broke. It will be hard enough to sustain the U.S. effort in Afghanistan, to say nothing of undertaking a new challenge in North Korea.

And finally, Barack Obama is not George W. Bush. Obama comes out of the peacenik wing of his own party. Where he comes from, in the lefty precincts of Harvard or Hyde Park on Chicago's South Side, the goal has been to contract American military power around the world, not to extend it.

But Obama is not in tofu-town any more, he is in the White House. And he does have to do something about North Korea. If he relies on cheerleading from The Washington Post and the rest of the MSM, he might be able to convince himself that more "diplomacy" will do the trick in North Korea, and maybe also in Iran.

Yet, as Ronald Reagan once said, "Facts are stubborn things." If North Korea and Iran develop into full-fledged nuclear powers, possessing delivery mechanisms for those nukes, well, that would be a difficult and dangerous fact for America and the world.

And because this is a really important issue, it's worth pausing to consider: What's the actual danger that North Korean nukes might pose? The immediate answer: They might soon be able to launch a nuclear-tipped missile. As Obama said on Monday, "North Korea's attempts to develop nuclear weapons, as well as its ballistic missile program, constitute a threat to international peace and security."

Incidentally, there is the danger, too, that North Korea might illicitly ship plutonium elsewhere in the world, but the proximate issue is that the North Koreans could annihilate Seoul, or Tokyo, or maybe some part of the U.S. It wouldn't make much sense for them to do that, but no country can survive by relying solely on the good sense of other countries.

Yes, it's true that we can't stop North Korea's nuclear weapons program. But we can stop North Korea's ballistic missile program--or at least its reach.

And so the answer, of course, is missile defense. Is it expensive? Sure. Is it a sure thing? No. Well, actually, over time, it is close to a sure thing, because it just takes the right sort of know-how and perseverance, the sort of "can do" spirit that America has displayed over the centuries. If that can-do-ism seems to be in short supply now, that's a mission for Obama and his TelePrompTer.

America needs a plan for its own defense and the defense of its allies. And right now, we don't have one. Talk is cheap, especially at the UN. And international sanctions are iffy, especially when most countries don't care. But nuclear weapons are real. And so Commander-in-Chief Obama needs to figure out how to keep nukes from coming here.

James P. Pinkerton is a Fox News contributor. He is a former White House domestic policy adviser to Presidents Ronald Reagan and George H.W. Bush.