The White House’s proposed amendment to the U.S. law that prevents direct payments to Russia for space station hardware and services is long overdue and should be approved as quickly as possible.

The amendment to the 2000 Iran Nonproliferation Act (INA), submitted to Congress the week of July 4, would strike the provision that bars NASA from buying or bartering for Russian goods and services associated with the space station. Without the change, NASA would no longer be able to occupy the outpost on a full-time basis after April 2006, which is when the last of the Soyuz crew capsules Russia agreed to supply for free is slated to undock from the facility and return home.

The Bush administration first notified Congress that it would seek unspecified changes to the INA in a June 28 letter signed by Secretary of State Condoleezza Rice and NASA Administrator Mike Griffin. The letter was publicized by Mr. Griffin at a congressional hearing that day.

The move sends a strong signal to the Russians, as well as NASA’s other space station partners, that the United States intends to address an issue that has left a cloud of uncertainty over the space station program. The White House also served notice to Capitol Hill that it is mindful of its own prerogatives in foreign and nonproliferation policy, and perhaps that in the rarified air of national goals and priorities, civil space counts too.

Soyuz vehicles are indispensable if NASA and its partners are to get any meaningful scientific return from the billions of dollars they have spent on the space station. After ferrying up to three astronauts to the space station, each Soyuz spacecraft remains docked there for six months, providing the only means of evacuation should something go awry. After six months, the docked vehicle is used to take crew members back home after new occupants arrive aboard another Soyuz.

The return of NASA’s space shuttle to flight this summer does not change this equation significantly. While shuttles can ferry people to and from the space station, they can only remain docked at the outpost for about two weeks at a time, and thus are unsuitable as lifeboats for crews on longer-duration visits.

When shuttles resume the task of assembling the space station, adding the European and Japanese modules, the gap between the station’s capacity and its utilization will grow even wider.

Officials in NASA and the White House have long recognized this, but also are properly sensitive to the concerns that led to the passage of the INA.

Lawmakers and others in the U.S. government have long suspected Russian companies of aiding Iranian weapon development programs. The INA requires the White House to certify that any Russian entity from which NASA seeks to buy space station goods and services is not among the offenders. Meeting that requirement would be very difficult from both a political and a practical standpoint.

But the INA is flawed, in part because its authors failed to take into account future yet plausible developments affecting the space station.

First there was the cancellation of NASA’s Crew Rescue Vehicle following revelations of a multibillion-dollar space station cost overrun, a move that left the space station partners completely dependent on the Soyuz for crew escape. To their credit, some of the INA’s authors warned years ago about the space station program’s dependence on Russia. On the other hand, there might not even be a space station today without Russia, and if there were, it would almost certainly be a very expensive and uninhabited shell with the space shuttle fleet grounded following the February 2003 Columbia accident.

That tragedy led to an overhaul of U.S. space policy and its goals, including a decision to retire the space shuttle fleet by 2010. Mr. Griffin is looking for ways to keep the number of remaining shuttle flights to the absolute minimum, and that likely means dramatically cutting back on space station utilization flights. And that, in turn, means there will be fewer opportunities for crews to visit the station for even short-duration stays.

The other major problem with the INA is that it represents a glaring inconsistency in U.S. nonproliferation policy. The U.S. Department of Defense currently launches national security payloads on Atlas 5 rockets powered by Russian-built RD-180 engines. Energomash, the manufacturer of the RD-180, does not provide these engines for free.

Making exceptions in cases such as the RD-180 only serves to undermine a U.S. nonproliferation policy that is based on applying leverage against Russia’s aerospace industry. The contradiction inherent in the RD-180 exception cannot simply be dismissed on national security grounds — the Pentagon has a readily available alternative to the Atlas 5 for launching national security payloads in Boeing’s Delta 4 rocket.

For NASA, meanwhile, there is no near-term alternative to Soyuz for space station crew rescue, something NASA is obligated to provide under its agreements with the other station partners.

No less a nonproliferation hawk than Rep. Dana Rohrabacher (R-Calif.), one of the principal architects of the INA, conceded recently that the law has proven ineffective.

Even so, amending the INA could prove troublesome politically. The House Armed Services Committee, in the report accompanying its version of the 2006 defense authorization bill, called the INA a “critical tool” in preventing the flow of weapon technology to Iran and said it will take a dim view of any attempt to amend the measure in the name of “lesser policy priorities.”

As it seeks to do just that, the Bush administration can rightfully ask these and other congressional skeptics exactly what greater policy priorities the INA is actually serving.