In the last few weeks, a former president traveled to North Korea to negotiate the release of two imprisoned Americans; a U.S. senator flew to Burma to bargain for the release of yet another American; and envoys of the reclusive North Korean regime have come to the U.S. for talks with America's former ambassador to the United Nations.

And throughout all of it, one question grows: Where is America's top diplomat, Secretary of State Hillary Clinton?

The missions by former President Bill Clinton and Virginia Sen. Jim Webb to secure the release of Americans held in North Korea and Burma detoured sharply around Clinton's State Department.

And two diplomats from North Korea were meeting privately Wednesday with New Mexico Gov. Bill Richardson -- a Clinton family pariah whose decision to back Barack Obama in last year's presidential campaign earned him a barbed comparison to Judas. 

These developments certainly have not curbed the narrative that Clinton has been marginalized in the Obama administration. 

"She has been the most low-key secretary in recent times," said Nile Gardiner, director of the Margaret Thatcher Center for Freedom at the conservative Heritage Foundation. "There does appear to be two different tracks of U.S. diplomacy at this time: One headed by Hillary Clinton and another headed by an array of different figures....

"What we have is an immensely confusing patchwork of foreign policy initiatives without any real central coherence." 

This "mercenary-style approach," Gardiner said, enables U.S. adversaries to adopt a "divide-and-rule strategy" with the Obama administration.

Observers have noted that Clinton has a particularly contentious relationship -- or non-relationship -- with officials from North Korea, which could pose a barrier to both sides in future negotiations.

In a bizarre name-calling exchange last month during Clinton's trip to Asia, she compared the North Koreans to "unruly children" demanding attention, and Pyongyang's foreign ministry retaliated by calling her a "funny lady" who sometimes "looks like a primary schoolgirl and sometimes a pensioner going shopping." The ministry was quoted as calling her remarks "vulgar" and saying "she is by no means intelligent." The State Department returned fire with another tapestry of put-downs. 

So perhaps it came as no surprise when Kim Jong Il summoned not the secretary of state, but her husband -- more of a rock star, less of a prickly pear -- in exchange for the release of two jailed American journalists. 

But the global fanfare surrounding the mission and its successful conclusion appeared to get under the secretary's skin, though the Obama administration was still involved in the North Korean operation. 

In a flash-in-the-pan moment that came to overshadow pretty much all positive aspects of her lengthy tour through Africa, Clinton snapped at a university student in the Congo who asked her what her husband thought about a multibillion-dollar Chinese loan offer. 

"Wait, you want to know what my husband thinks?" she responded. "My husband is not the secretary of state. ... I am not going to be channeling my husband." 

For a secretary of state who was recently grounded due to a broken elbow, contributing to speculation that she was being sidelined, the student's question was quite literally adding insult to injury -- though it turned out the student apparently meant to ask about President Obama's opinion. 

On top of that, Webb, who chairs the Senate Foreign Relation Committee's East Asia and Pacific Affairs Subcommittee, just secured the release of American John Yettaw, who was sentenced to seven years in jail in Burma for sneaking into opposition leader Aung San Suu Kyi's home. 

In another duo of breakthroughs, Webb met with Senior Gen. Than Shwe and Suu Kyi herself - though Suu Kyi's detention still stands. 

Now Richardson, who has previously traveled to North Korea on special missions, is hosting diplomats from that country in his home state. Emerging briefly from talks he told reporters Wednesday the session is a "hopeful sign" of improving ties. 

Reportedly, the North Koreans once again requested the terms for the meeting. And the governor's office is saying Richardson is not representing the Obama administration. 

So who is? 

Robert Schadler, senior fellow in public diplomacy at the American Foreign Policy Council, said these meetings set an unhelpful standard. 

"It does set something of a precedent and it allows the other side to appear to gain more because they've gotten their negotiator of choice," he said. 

But Schadler said when American prisoners or hostages are involved, particularly in countries where the United States does not have formal diplomatic relations, it presents a tricky situation for the diplomatic establishment in Washington. 

The administration, he said, does not want to encourage American hostage-taking by returning every imprisonment with an official visit from Washington. It also does not want to breach its own longstanding decision to sever ties with those countries. 

Instead, Schadler said, hostage negotiation falls in the hands of "people in the gray area," which presents another problem in that these people are not always publicly vetted for that job. 

Looking ahead, Clinton has another pair of diplomatic challenges, which she has so far handled from afar. 

One is the detention of three American hikers in Iran. Last weekend, Clinton renewed the call for them and others to be released, issuing a statement to "once again urge Iran's leadership to quickly resolve all outstanding American citizen cases." 

According to Britain's Sky News, she has also urged Scotland's justice system not to release Abdelbaset Ali Mohmed al Megrahi, convicted in the deadly 1988 bombing of a Pan Am flight over Lockerbie. The Libyan government wants Megrahi transferred to Libya. 

In Clinton's favor, public opinion seems to be on her side, even as Obama's approval numbers drop. 

The latest FOX News poll, of 900 registered voters last week, showed 66 percent of people approve of the job she's doing as secretary of state. Obama's approval rating was at 53 percent.