Last week in Berlin, President Obama embarked on another arms control gambit with the Russians. Not content with the one-sided New START deal that let Russians increase their nuclear weapons while the U.S. cut its arsenal, Mr. Obama is at it again.

But this time will be harder. The Russians are less interested, and senators who felt burned by New START don’t want to be fooled again.

The Russians got most of what they wanted in New START. They launched the most extensive nuclear modernization program since the end of the Cold War, and the U.S. must cut its strategic nuclear warheads by 250 over New START’s seven-year implementation phase. They already have a 10-1 advantage in tactical, or shorter-range, nuclear weapons, which they want to keep. Also, unlike Mr. Obama, Russian President Vladimir Putin doesn’t believe in the “road to zero.” He finds it a fantasy that would undermine Russia’s strategic power.

The Russians may agree to new talks to test how far the U.S. will go. They are always looking for ways to limit U.S. missile defenses and may realize that their huge advantage in tactical nuclear weapons gives them negotiating leverage over American strategic forces.

Whatever they do, they will never go to zero or do anything else that endangers their nuclear arsenal.

Many of the arguments trotted out for New START in 2010 won’t fly today. One was that if the U.S. cuts its nukes, others will do the same. As Michaela Dodge of the Heritage Foundation argues, “Since the end of the Cold War, the U.S. has eliminated around 80 percent of its nuclear arsenal. No other nation has followed suit. Yes, South Africa gave up its nukes, but that happened while the U.S. was testing its weapons and expanding its arsenal.”

She then reminds us that since the U.S. began drawing down its nuclear forces, North Korea and Pakistan have emerged as nuclear powers and Iran is “nipping at their heels.”

Another argument that has not improved with age is, as Mr. Obama puts it, “so long as nuclear weapons exist, we are not truly safe.”

Nuclear weapons are not animated objects in control of their own fate. They don’t hover above the Earth as if suspended by some mystical force. They belong to specific governments. The U.S. and Russian arsenals are not the problem; it’s those of North Korea, Pakistan and potentially Iran. Another round of talks with the Russians will do absolutely nothing about these arsenals.

The administration made a number of promises at the time the Senate ratified New START. Most of them, alas, already have been broken. Sufficient funds to modernize U.S. nuclear forces were not forthcoming. Moreover, the president promised to speed up construction of the Chemical Metallurgy and Research Replacement Nuclear Facility at Los Alamos NationalLaboratory when the treaty entered into force, but the project has been delayed by five years.

Senate Republicans are in no mood to be hoodwinked again. Fearing that the administration may do an end run around them, Sen. Marco Rubio of Florida and several other GOP senators wrote to Secretary of State John F. Kerry demanding that further reductions be “conducted through a treaty subject to the Senate’s advice and consent.” The concern is that Mr. Obama will cut some nontreaty agreement with Moscow that would not need Senate ratification.

New START was not a slam-dunk for the administration in 2010. It had to ram the treaty through a lame-duck session — when the Senate should have been away for the holidays before the next Congress was sworn in, and when the Democrats had more votes and the Republicans were distracted by other matters.

It won’t be so easy this time. Senators are on guard, and many fear that further reductions of the U.S. arsenal will benefit not only the Russians but also the Chinese, who are modernizing their nuclear forces just as Moscow is doing, but who are not even part of the deal.
The second time will not be a charm.

- Kim R. Holmes, a former assistant secretary of state, is a distinguished fellow at the Heritage Foundation.