Last week’s UN Security Council vote authorizing the imposition of a no-fly zone and other measures against Muammar Gaddafi’s forces in Libya was something less than an emphatic mandate. A number of observers have noted the unusually high number of abstentions, and that all of them came from such major international players as Germany, Brazil, India, Russia, and China.

The votes by Brazil and India did not come as a great surprise. Both countries have long records of skepticism about military adventurism—even adventurism under the color of international authority. Germany’s abstention raised more than a few eyebrows, since it signaled a clear policy breach between Berlin and its traditional NATO allies (and European Union partners) Britain and France, as well as the United States.

But the most significant development was the decision of both Russia and China to abstain. Since they are among the five permanent members of the Council, a negative vote by either country would have vetoed the resolution. Given their repeated, vocal assertions about the importance of respecting national sovereignty, and their previous wariness about giving a UN imprimatur to military interventions, many experts in the weeks leading up to the vote expected one or both countries to cast a veto. After all, the United States and its allies bypassed the UN Security Council regarding both the Kosovo war and the Iraq war precisely because they knew that “no” votes from Russia and China were virtually certain.

Their decision to abstain on the Libya resolution begs the question of why they were so cooperative this time. And that leads to a subsidiary question relevant to all political outcomes, domestic or international: what concessions did the winning party (in this case, primarily the United States) have to make to gain its policy victory?

We may not be able to determine that answer with any certainty for months or years—or conceivably not for decades, when the pertinent documents are declassified. But there is little question that there had to be concessions. Neither Moscow nor Beijing regards foreign policy as an altruistic enterprise. The United States paid something to get them to abstain rather than cast a veto.

What Washington paid is, of course, pure speculation. But there are a number of probable candidates, and we should watch for indications over the coming months and years. For example, China has always wanted Washington to decrease and eventually eliminate its arms sales to Taiwan. Will the Obama administration be less receptive to Taipei’s future arms purchase requests? Beijing is increasingly unhappy about U.S. criticism of its policy in Tibet and general human rights policy. Do U.S. leaders now become much quieter about those controversial matters? Will Washington’s policy toward North Korea soften and correspond more closely to China’s preferences? Will allegations about Beijing’s currency manipulation or the PRC’s insufficient respect for intellectual property rights decrease in both frequency and intensity?

With respect to Russia, will we hear far fewer calls for further enlargement of NATO, including eventual membership for Ukraine and Georgia? Will the Obama administration mothball plans for even a limited missile defense system in Eastern Europe? Will Washington become more understanding of Russia’s annoyance at the discrimination against Russian-speaking minorities in the Baltic republics? What about Russia’s ambitions to join the World Trade Organization?

There are no clear answers yet to any of these questions, but the questions deserve to be asked. It would be naïve in the extreme to assume that the United States secured its diplomatic victory in the Security Council without having to make some significant policy concessions to the two permanent members who reluctantly withheld their vetoes.