imf and the world bank still operate and are needed, but as alternative sources of credit and capital take their place, few countries look to them for guidance. in new york, the united nations, which gained momentum in the cold war ended, has been sidetracked. as for u.n. peacekeeping, it is given the assignments that no one else wants. back when i was ambassador of the united nations, i was besieged by members of congress who worried that our sovereignty would be trampled on by world government. today, we should worry less about the ambition of multilateral institutions than because there are vital tasks that only they can do. when serving in the clinton administration, i felt america's goal was to bring nations closer together in pursuit of freedom, law, and peace. the obama team has the same objective, but the process has been made more complex by the trends. with so much going on, our leaders often have to proceed a case by case basis, improvising in the search for solutions to particular problems. in one case, we might turn to nato. we might have to act alone. at the same time, we have to strive to create more effective networks for addressing shared problems, such as