Raising concerns about a new nuclear arms treaty is considered declasse. It's about as welcome as a wedding crasher who questions the groom's choice of a bride.

Like weddings, nuclear treaties are supposedly joyous occasions. Posing questions is treated as an affront to the very nobility of the enterprise (although for some marriages and certain treaties, the prospective partners would have been better off answering questions before tying the knot).

Similarly, some people can't imagine how reducing the levels of nuclear arms in the United States and Russia could possibly be a bad thing. They think the problem is that nuclear weapons even exist. That these weapons, in the right hands, may help keep the peace is hard for them to understand.

One of those people is President Obama. Announcing a new Strategic Arms Reduction Treaty (START) with Russia last week, he said, "Today, we have taken another step forward in leaving behind the legacy of the 20th century." The "dark" legacy of the Cold War, Mr. Obama believes, is the mere existence of nuclear weapons; thus, this agreement is a step toward "a world without nuclear weapons."

We could argue about whether nuclear weapons should have been invented at all. But they were, and they will remain part of America's military arsenal even under (and after) Mr. Obama. The real issue is not whether this agreement is a step toward removing some terrible legacy, but whether it will make Americans and the world more secure.

That's when embarrassing questions begin to crash the wedding. First, how, as the president claims, will this agreement "strengthen our global efforts to stop the spread of these weapons" in Iran? The assumption appears to be that if we lead the way with our own reductions, Iran will follow. But Tehran is unimpressed. It wants nuclear weapons not because we have them, but because it wants to intimidate us and its neighbors.

A smaller force is also not necessarily a better one. Without modernization and testing, we can't be sure the nuclear weapons we retain will actually deter aggression.

And what does the treaty language of "linkage" between reducing nuclear weapons and missile defense in the preamble of the treaty mean exactly?

The Obama administration claims the treaty includes no constraints on our ability to deploy missile defenses. The Kremlin disagrees. Its official statement says the treaty contains a "legally binding linkage between strategic offensive and strategic defensive weapons." Foreign Minister Sergei Lavrov says that Russia could even withdraw from the treaty if the U.S. proceeds with plans for missile defenses in Europe, which are intended to counter Iran, not Russia. You can bet Russia will use this treaty at every opportunity to try to stop further missile defense deployments in Europe.

There's also the question of verification. It has always been difficult to confirm the number of deployed warheads in Russia's arsenal. Because the new treaty limits warheads specifically, its verification regime should at least be able to account for all warheads - not just an estimate based on the number of warheads each launcher typically carries. The inability to verify the number of actual warheads in Russia's arsenal means it conceivably could load more warheads onto each launcher and exceed the total warhead number the treaty allows without getting caught.

The biggest mistake of this treaty, however, is that Mr. Obama is completely misreading Russia's intentions. Russia's nuclear and conventional weapons arsenals are declining faster than ours, due to age and funding, so of course they want to bring our levels down to theirs. But Mr. Obama doesn't seem to realize he is playing right into the Kremlin's strategy of relying more, not less, on nuclear weapons over conventional ones. The total number of nuclear weapons may shrink, but the net result of this treaty will be to accentuate the role of nuclear weapons, particularly in Russia's military planning.

Why? Because with this treaty the Russians are trying to constrain our advantage in conventional (non-nuclear) "strategic" weapons, including missile defense, in order to accentuate the power of their nuclear arsenal. So even if the overall levels of nuclear weapons are lower, their strategic importance would be greater in maintaining the military balance. This treaty thus codifies Russia's interest in maintaining the centrality of nuclear weaponry - subverting the administration's lofty intentions to use this treaty as a step toward universal nuclear disarmament.

Ultimately, if ratified, this treaty will indeed mean the death of any zero-nuke option. It feeds Russia's expectations that it can effectively challenge the U.S. and still maintain a peer relationship with us through its reliance on nuclear weapons. No matter what the Obama administration may think, the last thing the Kremlin wants is to junk these weapons.

The Senate will take its time to review this treaty. Two-thirds are required to ratify it. You can bet that many senators won't be rushed into a shotgun wedding. Nuclear treaties, unlike many marriages today, are very hard to get out of. Get them wrong, and worse things than a messy divorce can happen.

• Kim R. Holmes, a former assistant secretary of state, is a vice president at the Heritage Foundation (Heritage.org) and author of "Liberty's Best Hope: American Leadership for the 21st Century."