Stopping Iran's nuclear program. Limiting the growing influence of an increasingly authoritarian Russia over the former Soviet empire. Making more friends than enemies in the Arab world.
Those are just some of the major foreign policy challenges the Bush administration will confront next year. But to do that, experts say, it must shake off the legacy of 2005 - a year aimed at rebuilding America's bridges to the world that instead kept the US in the diplomatic doghouse.
Two disappointments, they say, stand out. First, despite some optimism earlier this year, America's allies still doubt whether the US has changed its unilateralist ways. And second, this year's domestic events - from the slow federal response to hurricane Katrina to the domestic spying controversy - are influencing US ties with the world as much as international issues.
"The administration didn't do quite as well at rebuilding bridges and reviving alliances as the early rhetoric suggested, and that is going to have a direct impact on the issues we face in 2006," says Nicholas Gvosdev, editor of the National Interest, a foreign policy review. America's allies and partners "have a sense that the administration hasn't measured up to the promise of renewed cooperation and consultation suggested at the beginning of the year," he adds.
The Bush administration did register a number of diplomatic successes - from cooperation with the European Union on Iran and new dialogue with North Korea, to pressure on Syria, in tandem with France, over its influence in Lebanon.
But recent revelations of clandestine prisons for terror suspects and other secret antiterror operations - including renditions of suspects to other countries involving unreported stops in allied nations - are likely to have a deep impact on issues the US seeks to address with international partners.
There's a particularly strong sense among Europeans, Mr. Gvosdev notes, that the US simply bypasses them when it finds it inconvenient to work together. "That sentiment could very well bite back at the administration as it seeks to develop cooperation on other issues," he says.
On Iran, for example, he says that "reactivated suspicions of the US" among Europeans means they have stepped back from a tacit US-Europe agreement to move beyond negotiations to at least United Nations Security Council action - and perhaps something more forceful - if European talks with Tehran failed.
Another early test of US relations with its European allies could come during elections in Belarus, scheduled for March.
Earlier this year, Secretary of State Condoleezza Rice said that Belarus was Europe's "last true dictatorship." Russian Foreign Minister Sergei Lavrov countered that reform should not be imposed from outside.
Most experts anticipate that the elections in Belarus will not be free and fair, so observers will be watching how Russia - and Western Europe - respond to potential postelection controversy.
A similar test could arise in Southeast Asia, where the Bush administration is encouraging its partners there to apply pressure for reform of the military dictatorship in Burma (Myanmar). The US is expected to move for a UN Security Council resolution on Burma as early as January, and will be looking for support from Asian countries including India, Japan, the Philippines, and Thailand.
The Bush administration has also made improving America's image abroad a priority. Its importance was underscored when Bush named one of his closest advisers, Karen Hughes, to head up the State Department's public diplomacy efforts, a job she took on in earnest in the fall.
But a string of events that undercut the ideals it espouses to the world hurt America's public-relations effort, experts say.
"What Katrina exposed, the questions over renditions and torture of terror suspects, and now the domestic spying controversy - all of this has really hit our image hard around the world," says Lawrence Korb, a former Defense Department official in the Reagan Administration now at the Center for American Progress in Washington.
Mrs. Hughes has acknowledged that the task of promoting American ideals abroad is more difficult that she anticipated. With global access to - and interest in - US news so high, efforts to discuss democracy and human rights abroad are often clouded by American issues such as race relations, the death penalty, or domestic spying.
"I was in Europe when all the hoopla broke over Bush's authorization of domestic spying, and what I kept hearing from people was, 'You guys sound like the Soviet Union during the cold war,' " says Mr. Korb.
The US scored high points and won some hearts with its outpouring of aid after the South Asian tsunami and, to a lesser extent, with its response to the Paki- stani earthquake. "But on balance I'd say we had a net loss," Korb adds. "Unfortunately, these other issues dominated that expose the US to charges of hypocrisy."
In 2006, Iraq and the success or failure of its political evolution will continue to play a major role in influencing how other countries respond to US initiatives. But if anything, the Iraq experience will probably remain a wedge between the US and its partners, sapping their enthusiasm for joining US efforts at spreading democracy that some leaders contend can be dangerously destabilizing.
"The hope in Washington was that 2005 would be the year Iraq would be put behind us [diplomatically]," says Gvosdev. "But that didn't happen, and it's not likely to happen next year, either."