President Bush has softened the U.S. stance against Iran and North Korea, trying to bargain with regimes he once lumped with Iraq in an "axis of evil."
But the results in his second term are largely the same as in his first - nuclear standoffs against nations that define themselves by their opposition to U.S. policies even as they angle for Washington's attention.
The twin impasses are coming to a head this election-year summer at the same time that U.S. military deaths are trending up in Iraq, support for the war is dropping at home and the Bush administration is scrambling to respond to a resurgent Taliban in Afghanistan.
North Korea set off an international furor last week when it test-fired seven missiles that plunged into the Sea of Japan, including one with the theoretical ability to reach U.S. shores. The secretive communist nation is boycotting international talks that would trade economic rewards for an end to the North's declared nuclear weapons program.
Iranian response due this week
Bush and other world leaders want an answer from Iran this week on whether the clerical regime will accept a similar deal that would provide economic benefits and technical help with a peaceful nuclear energy program while reassuring the West that Iran cannot build a bomb.
After invading Afghanistan and Iraq in his first term, Bush insists that diplomacy can counter the threats posed by Iran and North Korea. He tries hard to sound patient, as he did during a news conference Friday in Chicago.
"You're watching the diplomacy work not only in North Korea but in Iran," Bush said. "It's kind of painful in a way for some to watch, because it takes a while to get people on the same page. Not everybody thinks the exact same way we think."
Under the leadership of second-term Secretary of State Condoleezza Rice, the Bush administration has muted a foreign policy bullhorn that sounded belligerent or isolationist, even to longtime allies such as Canada, France and Germany.
Bush and Rice have cultivated alliances with European and other partners to present a common front to Tehran and Pyongyang. They have pressed for a unified international response, and sanctions if need be, from the United Nations Security Council.
Defusing the Iranian and North Korean nuclear threats after years of enmity with both countries could define Bush's second-term foreign policy legacy almost as markedly as Iraq defines his first.
So far, there have been hopeful signs but no permanent solutions.
After a meandering start in Bush's first term, six-nation talks that include North Korea and the United States appeared to bear fruit last fall. The North agreed to give up its weapons of mass destruction, although the terms were vague.
But the deal faltered almost immediately. Pyongyang walked away from the talks in December after the United States imposed what it says are unrelated financial sanctions. After ending its voluntary moratorium on missile tests this week, the North said it has the right to test weapons in self-defense.
Rice decided to reverse course on Iran this spring, convincing Bush that the United States risked losing its hard-fought international backing if it refused to sit face-to-face with Tehran and offer incentives. Iranian leaders seemed pleasantly surprised if a bit unnerved at the gesture.
The Bush administration won international backing for eventual penalties for Tehran if it rejects the deal. Iran has said it has questions about the carrot-and-stick package, and won't meet next week's unofficial deadline for a response.
International diplomatic success will require help from Russia and China, nations that have taken a dim view of U.S. efforts to impose punitive sanctions on both Iran and North Korea.
Boston University professor of history and international relations Andrew Bacevich says the administration can claim success in one respect - the second term has not brought a new war.
"If we were to take the rhetoric of the first term seriously about the axis of evil and the possibility of nuclear war, for goodness sakes we would probably be involved in four wars, not just two," Bacevich said.
He said the administration is merely accepting reality forced on it in Iraq.
"We are stuck in a war that is absorbing the energy of the national security apparatus and that in itself limits our capacity to even think about military operations in other cases," he said.