The calculation here is that arms control remains a zero sum game -- a tabletop exercise where nuclear supremacy is the goal. And that's where Romney's main assumption begins to drive the examples he's choosing: America's national security must never be impinged by its obligations to any other state. Doing so fundamentally projects weakness and subjects American actions to the veto of other nations.
This isn't unilateralism per se as much as it is an effort to forcefully reorganize the world to fit the contours of a different era, one in which the U.S. and China, for example, were not economic competitors, in which India did not steal high-tech jobs from the U.S., in which Russia felt constrained to assert its own interests outside the sphere of the former Soviet Union.
Politically, it's peacockery; Kaplan more politely calls it "swagger."
The START treaty does interlink the U.S. with Russia in several ways that Romney might find distasteful. But it also binds the countries closer together in ancillary ways that make the world safer: it fosters cooperation in getting other countries to give up their fissile materials; it allows for dialogue on issues like tactical nukes. But it does not bind the U.S. to anything and provides plenty of outs. Negotiators built in flexibility to allow for inspections to occur in an unprecedented manner. The treaty was never intended to address the issue of tactical nukes -- that's much more difficult. Romney complains that there is no mention of these nukes in the treaty, but that, in and of itself, contradicts the main point that he's making: that Obama is giving away too much. Had Obama elected to add tactical nukes to the table, that would be -- well, probably a treaty killer, but also something that no one, not even NATO allies, really wanted.
Romney believes that U.S. interests are best served if Russia lives in fear of the U.S., rather than both countries feeling as if their equities are served by a stable nuclear relationship. Here, Romney might want to channel his inner Ronald Reagan, that apostate on arms control, or even the Republican foreign policy consensus that has developed around arms control. For Romney to make a clean break with Obama, he needs to explain why Stephen Hadley (who is critical of some parts of the treaty but not with the philosophy that underpins it), Henry Kissinger, James Baker, James Schlesinger, and Richard Lugar, among others, are approaching START from such a different vantage point. In point of fact, the START treaty is rather anodyne. U.S. missile defense prerogatives are built in to its preamble. The Secretary of Defense supports it, as does the entire nuclear bureaucracy.
In any event, Romney is signaling that he'd take American foreign policy in a radical old direction, back to the days of confrontation and brinksmanship. This re-Boltonization on arms control is not out of the ordinary for Romney. He subscribes to an essentialist model of the world, where humility is only used as a preamble to assert strength, project strength, be strong. The defect of this model is that events have discredited it, and that is not equipped to tackle transnational threats. Republican primary voters seem to feel comfortable with the rhetoric, but if the rhetoric is taken to its logical conclusion, America will wind up hobbled and humbled by magical thinking.
The fact is that foreign policy is perhaps the one area on which Americans are comfortable with President Obama's leadership. They give him respectable marks for his policies and high marks for his commander-in-chief portfolio. Even as Americans disagree with Obama on the wisdom of closing Guantanamo Bay, they do not perceive him to be weak on foreign policy, or dangerously incompetent, or naive. If foreign policy is where Romney wants to intervene, he has his work cut out for him.