Russia is ratcheting up the pressure on Washington to find a way to pay for Soyuz missions to the international space station starting in April 2006, but U.S. officials should not let themselves be rushed into anything, even if it means having no permanent American crews aboard the orbital facility for the foreseeable future.

Committing now to the payments Moscow demands would require weakening or circumventing the 2000 Iran Nonproliferation Act (INA). That U.S. law bars NASA from paying for Russian space station hardware and services unless the White House can certify that no entity even loosely tied to Russia’s space agency is still selling weapons technology to Iran.

This is a delicate situation that needs to be handled in a careful deliberative process. Iran’s pursuit of weapons of mass destruction and proliferation in general are very serious issues, and while tying them to the international space station program was shortsighted in the first place, scrapping or diluting the INA under duress is not likely to yield a better policy. Nor is it likely to result in what’s best for NASA or the space station program.

Under a bilateral accord with the United States signed in 1996, Russia is obligated to send Soyuz crew capsules and Progress cargo vehicles to the space station free of charge until April 2006. Russia is perfectly willing to continue providing the vehicles after that time, but expects to be paid accordingly.

The Soyuz contract flights would begin in theory with Expedition 13, which is slated to launch in April 2006. That should leave some time to find a solution to the INA problem that does not make a mockery of U.S. legislative processes and nonproliferation policies, but some Russian space officials apparently want to force the issue.

They have gone so far as to threaten to bar a U.S. astronaut crew from training for the Expedition 13 mission at the Gagarin Cosmonaut Training Center pending a guarantee that payment will be forthcoming.

It is understandable that cash-starved Russia wants to get paid for its hardware and services, but Moscow must recognize that U.S. laws — especially ones dealing with political hot-button issues like proliferation — are not easily overturned, watered down or ignored.

Congress and the White House know full well that any attempt to strip the space station provisions from the broader INA will leave supporters of the move vulnerable to charges that they are not serious about containing proliferation. With the United States and Iran locked in a simmering feud amid suspicions that Tehran is developing nuclear weapons, it just isn’t the smart thing to do politically.

Clearly there is no near-term alternative to the Soyuz for keeping the space station permanently occupied. The United States put itself in that position when it canceled its own version of a space station crew lifeboat back in 2001 . The space shuttle, expected to resume flights this May after a hiatus of more than two years, is limited to two-week stays at the orbital facility.

But even without a resolution to the INA issue, the space station need not sit idle in between the four shuttle visits planned for 2006. There is nothing that bars the Europeans or Japanese from paying Russia to launch their astronauts for extended stays aboard the station. In fact, by making more crew capacity available to its international partners in the near term, NASA could help cushion some of the blows that are sure to come given the United States’ determination to trim the number of space station assembly missions on the shuttle manifest.

Further, NASA is revising its space station research agenda with an eye toward limiting it to those experiments that contribute directly to the president’s vision for returning astronauts to the Moon by 2020. Between the long-term station crews and visitors whose stay is limited by the length of a shuttle mission, NASA may well be able to fulfill most if not all of its more-focused research agenda. Missions to Mars are still a long way off, so NASA has plenty of time to figure out ways to prepare for such long-duration journeys.

NASA remains obligated to provide an emergency crew return capability for at least four non-Russian space station astronauts — Russian crews presumably will have their own rescue vehicle — once assembly is completed. But that milestone is still years away, which should give the White House and Congress enough time to sort out the INA issue — provided they start working on them now.

The one thing NASA and the White House should not do is hit the panic button or seek to reconcile its nonproliferation and space policy goals in a crisis mode. As the space station situation demonstrates, it is always better to take the time to get things right the first time around. That should have been the case when the INA was crafted, but watering it down now sets a bad precedent. Russia is notoriously patient in negotiations with other countries. It is high time the United States exhibited similar restraint.

Russian officials have indicated they are willing to be flexible if they get a sign from the United States that progress is being made on this issue. They can help that progress by doing something about proliferation, which is as great a threat to Russia’s citizenry as it is to the people of the United States.