U.S. President Barack Obama came to office promising to explore ways to talk with countries hostile to the United States -- such as North Korea and Iran -- in what was regarded as a stark contrast to the Bush administration's labeling them as parts of an "axis of evil."
He reiterated that approach just a week after taking office in January, pledging that "if countries like Iran are willing to unclench their fist, they will find an extended hand from us."
But on May 25, North Korea appeared to give a stunning reply. It conducted its second nuclear test -- its first during Obama's term -- and produced an explosion experts compare with those that flattened Hiroshima and Nagasaki during World War II.
Pyongyang followed that explosion with the test-firing of three short-range missiles one day later, despite the UN Security Council unanimously condemning the underground nuclear test on May 25.
Obama responded by saying United States and its allies would "stand up" to Pyongyang, and U.S. Ambassador to the UN Susan Rice vowed "to pursue a strong [Security Council] resolution with teeth."
Separately, but also this week, Iranian President Mahmud Ahmadinejad said the time for talking with the West about its own nuclear program is finished.
Ahmadinejad said on May 25 that "the nuclear issue is over for us." He added, "We will not talk about the nuclear issue with those outside the IAEA," the UN's nuclear agency.
Pushing For Rethink
The events in North Korea and Iran have created a flurry of warnings to Obama from critics who say he should give up his announced readiness to reach out to America's enemies.
A former U.S. ambassador to the UN under the Bush administration, John Bolton, said "the North Koreans have thumbed their nose at the [Obama] administration, and now we have to see what kind of stuff they are made of."
A key question for Washington is whether the actions in North Korea and Iran reflect final foreign policy decisions in those countries, or are tied to domestic issues -- meaning there still could be a possibility of talks with Washington.
Aidan Foster-Carter, an expert on Korea at the University of Leeds in Britain, says Pyongyang's main goal may be to reassert the regime's power as it faces a succession problem at home. He notes that President Kim Jong-Il suffered a stroke late last year and there is still no clear designee among his three sons to replace him.
"This may seem rather strange behavior [from Pyongyang], but I think this is a possible explanation: they are trying to accomplish this very delicate business of a succession, and so they would make a lot of noise and be militant just so the rest of us leave them alone at a time when they feel vulnerable," Foster-Carter said. "It doesn't necessarily follow that they will stick with this bellicosity."
But the analyst also said that North Korea may have made up its mind to be a nuclear-armed state and no longer has any intention of negotiating seriously with the West, despite Pyongyang frequently saying it wants to talk directly with Washington and the Obama administration's openness to such talks.
'At Face Value'
"If you took the sort of thing they have said in the past or are thought to believe at face value, namely, that all they want is for the U.S. not to be hostile and so on, then, if they had been following Obama at all they would know that they do have a U.S. president genuinely committed to talk to countries that the U.S. has previously regarded as foes," Foster-Carter said.
"And we know that isn't just talk, he has already started and we are already seeing changes with say, Cuba, for example," he added. "So if North Korea really wanted that, you could say that the door was in principle open, they didn't really need to blow it open with a missile or a bomb which, if anything, is just going to make stuff harder."
Under a six-party deal with the United States, China, Japan, South Korea, and Russia in 2007, North Korea agreed to dismantle its weapons-grade nuclear program for energy aid. But progress stalled late last year amid disputes over disarmament verification steps.
Most recently, Pyongyang said it would quit the talks and restart its plutonium-making program after the UN Security Council condemned its launch of a long-range missile in April.
The uncertainty surrounding Pyongyang's motives for this week's tests make it difficult for Washington to respond immediately beyond the action already taken at the Security Council, leaving the Obama administration on its own as it faces domestic pressure to find tougher responses.
Bolton, for example, urged Obama to put North Korea back on the U.S. State Department's list of state sponsors of terrorism, something that would move Washington back in the direction of the Bush-era "axis of evil."
Tough In Tehran
Similar uncertainties surround Tehran's stance.
In the run-up to Iran's June 12 presidential poll, Ahmadinejad has repeatedly burnished his hard-line credentials in an effort to contrast himself with his reformist challengers.
Last week Ahmadinejad accused his predecessor as president, Mohammad Khatami, of bringing "humiliation" on Iran by agreeing to suspend uranium enrichment from 2003-05 as a confidence-building measure with the West. Ahmadinejad's main reformist challenger, Mir Hossein Musavi, is backed by Khatami.
That again raises the question about Tehran, as about Pyongyang, of whether this week's confrontational moves are motivated by internal politics or reflect a hardening posture toward Obama.
Meanwhile, the time Obama has set for talking with Iran is diminishing. The U.S. president says he will give Tehran until the end of the year to show it wants to engage with Washington.
The reason for that deadline is U.S. fears that Iran is moving closer to acquiring a nuclear weapons capability.
U.S. Chairman of the Joint Chief of Staff Admiral Mike Mullen said in an interview on U.S. network television that "most of us believe that [Iran] is one to three years [away from acquiring nuclear weapons]." He added, "That is why this engagement, dialogue is so important."
The most direct response Tehran has made so far to Washington's engagement offer came this week amid all the tension over both North Korea's and Iran's nuclear programs.
Ahmadinejad on May 25 proposed having a face-to-face debate with Obama at the UN if he is reelected as Iran's president next month. He suggested the debate "study the root of world problems."
The offer underlines the dilemma for Obama. In order to negotiate effectively, the new U.S. president needs willing partners abroad and a respite at home from calls for a more confrontational U.S. strategy. As this week's events show, both conditions could prove elusive.