Senate ratification of the New START Treaty is an important step forward in U.S.-Russian relations and will also be useful in pursuing America’s broader nonproliferation goals. What remains to be seen, however, is how the ratification process will affect further progress in both of these areas. There is a danger that the treaty’s ratification will become a Pyrrhic victory.

The modest benefits from ratifying New START have been discussed widely. Conversely, a defeat for the treaty, particularly after President Obama’s risky double-down effort during the lame duck session, would have damaged the U.S.-Russian relationship and could well have unraveled already difficult cooperation on Iran. It would also have discredited not only the president and his administration, but America’s ability to negotiate and implement international agreements. For U.S. diplomacy to be effective, it requires a presumption that agreements with major powers will be ratified in the absence of strong reasons to the contrary. Whatever New START’s flaws, there were no strong reasons not to ratify it and the Senate acted appropriately. To paraphrase Winston Churchill, ratifying the treaty was better than the alternative.

Thus Senator John Kerry’s statement that the treaty is “historic” dramatically lowers the standards for evaluating Senate actions, especially at a time when no one really fears a U.S.-Russian nuclear confrontation. Perhaps most telling is today’s coverage in the New York Times; notwithstanding the paper’s frequent editorials, news executives put the ratification vote on page six.

More important, the gains from ratifying New START cannot be separated from the process—and the process is likely both to limit New START’s benefits and to impose costs in other areas. The administration argued that ratification during the lame-duck session was essential to avoid any further gap in mutual verification. This is a weak argument, however, in that there has already been a substantial gap since the original START treaty expired, neither side suspects the other of planning a nuclear attack, and each side has a technical ability to monitor the other’s weapons. In fact, an administration official speaking at The Nixon Center a few weeks ago essentially admitted that verification would only become a problem over a longer time frame.

Notwithstanding efforts to make a strategic case, the administration’s decision to press hard for ratification now seems to have been largely politically motivated, whether due to concern about securing more Republican support in the incoming Senate, the desire for a foreign-policy accomplishment to show that the president could still lead after the midterm elections, or some combination of both. With this in mind, it should not be surprising that politics also shaded the approach of some Senate Republicans to the treaty. It was precisely the treaty’s nonhistoric character that virtually ensured it would be subject to political as well as substantive scrutiny.

Had the lame-duck session not already been so contentious, this need not have been a particular problem. Several Senate Republicans indicated openness to supporting the treaty earlier in the session, including Senator Lindsey Graham and Senator John McCain. Senator Jon Kyl—seen by many as leading Republican opposition to the agreement—was actually quite careful to avoid saying that he opposed New START until almost immediately prior to the vote. Our own conversations with Republican Senate sources during the lame duck session suggested that several additional Republicans could have voted to ratify New START under other circumstances; Senator Lamar Alexander is quoted in the press as saying that Republican anger over unrelated legislation cost five to ten votes. By the time the Senate reached New START, earlier conduct by Senate Democrats and the White House had alienated many Republicans who could have voted for the treaty.

That the administration secured thirteen Republican votes (including some from retiring Senators) for the treaty now—and had many more potentially within its grasp—makes clear what many had believed all along: it would not have been so difficult for President Obama to win the fourteen Republican votes needed for ratification in the new Senate, if he had been prepared to wait and to work more cooperatively with Senate Republicans. Senator Kerry’s comment that “70 votes is yesterday’s 95” ignores the reality that he and the White House could have secured many more than 70 votes had they handled the process differently and attempts to shift the blame for the low vote count onto Republicans.

Where this could cost the administration is in further politicizing U.S.-Russian relations, already the subject of heated debate. Doing more with Moscow would have been hard anyway, but pursuing objectives like U.S.-Russia or NATO-Russia missile defense—for example—will now be much more difficult. How many Republican senators will be prepared to support a meaningful missile defense agreement? Worse, where New START is at best a modest achievement focused on the U.S.-Soviet legacy, a successful cooperative missile defense project could be a game-changer for the future.

And missile defense is just one area where the administration could face intensified resistance and pressure. Because the U.S.-Russian relationship is still relatively fragile, and recent improvements are easily reversible, sharp disagreements could be quite damaging and could ultimately affect Moscow’s assistance on Iran and Afghanistan, two top U.S. security priorities.

It would advance important national interests if the administration is able to build successfully on New START to achieve some of the many things it claimed the treaty would facilitate, like an end to Iran’s nuclear program. But real accomplishments are likely to require that the administration deal with not only Russian leaders, but Republican leaders as well.