THE SENATE GOP’S INADVERTENT SUPPORT FOR IRAN…. Nearly all of America’s international allies have offered their enthusiastic support the pending arms control treaty with Russia, New START. There are, however, some foreign leaders siding with congressional Republicans. Mahmoud Ahmadinejad, for example, is hoping the GOP succeeds.

Last week, Richard Burt, the chief U.S. negotiator for the START-1 treaty with the former Soviet Union in 1991, explained, “[T]here are only two governments in the world that wouldn’t like to see this treaty ratified: the government in Tehran and the government in North Korea.”

Similarly, Max Bergmann, a nuclear non-proliferation policy analyst at the Center for American Progress, has noted, “This is a pivotal moment in not just U.S.-Russia relations, but also in Iranian-Russian relations. We don’t want to upset the current trajectory of where things are going, and that’s exactly what Sen. Kyl threatens to do.

This is worth fleshing out in more detail, because the meaning may not be immediately obvious to everyone. Why would Iran benefit from Republicans’ efforts? Elizabeth Weingarten explained this morning that solidifying U.S.-Russian ties leaves Iran even more isolated.

This past spring, Russia supported the UN Security Council Resolution to impose strict sanctions on Iran. In September, Medvedev agreed to not fulfill a standing contract of selling advanced air defense — S-300 surface-to-air missiles — to Iran. The contract was suspended, but not terminated. “Russia [was] willing to forgo money in order to make Iran’s nuclear weapons infrastructure more vulnerable to attack,” explains Micah Zenko, a fellow for conflict prevention at the Council on Foreign Relations. Russia pursued a tougher policy toward Iran in part because of the “reset” in its relationship with the U.S. This was a stark contrast to its earlier funding of Iran’s Bushehr nuclear reactor.

If the U.S. doesn’t ratify New START, experts say it will prove to Russia that the U.S. can’t deliver on its end of that “reset.” Failing to ratify New START could mean a diminished incentive for Russia to formulate its Iran policy based on U.S. objectives, especially because Russia has both economic and geopolitical incentives for maintaining a positive relationship with Iran. Selling Iran weapons is lucrative, and positive ties with Iran means Russia has a geostrategic advantage in the region.

Even if it doesn’t revive the surface-to-air missile contract, it could still back off on sanctions to Iran, and strengthen the Islamic Republic indirectly…. If foreign-policy analysts are right, waiting to ratify New START could have more serious consequences than those Republicans expect.

There’s already been some evidence of Republicans’ intending to sabotage the Obama administration’s Iran policy, but scuttling New START would be far more serious, and have more dramatic foreign policy implications.

Given GOP rhetoric on Iran, it’s tempting to think congressional Republicans wouldn’t take steps to strengthen Ahmadinejad, even indirectly. And yet, here we are.

Steve Benen

Follow Steve on Twitter @stevebenen. Steve Benen is a producer at MSNBC's The Rachel Maddow Show. He was the principal contributor to the Washington Monthly's Political Animal blog from August 2008 until January 2012.