WASHINGTON » Secretary of State John Kerry is practically home alone, toiling without permanent assistant secretaries of state for the Middle East, Asia, Europe and Africa. At the Pentagon, a temporary personnel chief is managing furloughs for 800,000 civilian employees. There has not been a director of the Internal Revenue Service since November, and a commerce secretary in nearly a year.

As President Barack Obama confronts a dangerous world and seeks to kindle an economic revival at home, the lights are off in essential offices across his administration. The vacancies are slowing down policymaking in a capital already known for inaction, and embarrassing a president who has had more than five months since his re-election to fill many of the jobs.

"I don’t think it’s ever been this bad," said Rep. Frank R. Wolf, R-Va., who recently wrote a letter urging Obama to act swiftly to fill top vacancies.

The White House is moving to plug some key holes this week, but there is still an enormous backlog, particularly at the State Department, where nearly a quarter of the most senior posts are not filled, including positions in charge of embassy security and counterterrorism. The Treasury Department is searching for a new No. 2, the Department of Homeland Security is missing its top two cybersecurity officials and about 30 percent of the top jobs at the Commerce Department are vacant, including that of chief economist.

At the Pentagon, which is helping to lead the administration’s "pivot" to a greater focus on Asia, the assistant secretary of defense for Asia is about to leave his job.

Kerry expressed frustration about the State Department vacancies in recent testimony before the House Foreign Affairs Committee, saying he was "still waiting for the vetting to move" at the White House for people he recommended for jobs "way back in February."

"I have a new appreciation for how much the confirmation process has become a political football in recent years and what that forces on the vetting process required to announce nominees," Kerry said in a statement to The .

Although Kerry said that "the White House and the administration make the very best out of a tough situation," who is to blame is a matter of intense debate.

The White House faults an increasingly partisan confirmation process in the Senate and what officials say are over-the-top demands for information about every corner of a nominee’s life. Treasury Secretary Jacob J. Lew received 444 questions from senators before his confirmation, more than the seven previous Treasury nominees combined, according to data compiled by the White House. Gina McCarthy, Obama’s nominee to lead the Environmental Protection Agency, got 1,000 questions from the Senate, White House officials said.

"Current congressional Republicans have made no secret of the extraordinary lengths they will go to to obstruct the confirmation process," said Eric Schultz, a White House spokesman. "That unprecedented evasiveness, often about matters decades old or unrelated to the post, slows down the process from beginning to end."

But members of Congress and a number of agency officials say the bottleneck is at the White House, where nominees remain unannounced as the legal and personnel offices conduct extensive and time-consuming background checks aimed at discovering the slightest potential problem that could hold up a confirmation. People who have gone through the vetting in Obama’s White House describe a grueling process, lasting weeks or months, in which lawyers and political operatives search for anything that might hint at scandal.

Administration officials, members of Congress and scholars of the federal appointment process say it is difficult to determine — short of a six-month-long study — if Obama has filled fewer of the roughly 1,200 federal jobs that require Senate confirmation than George W. Bush or Bill Clinton had at this point in their second terms. But there is widespread agreement that an alarming number of key posts in the government’s most senior ranks are vacant or filled with "acting" deputies with little authority to make decisions.

"It’s a weakening of accountability down the chain of command," said Paul Light, a professor at New York University who has done extensive research on the federal appointment process. "You don’t have someone there who has full authority to say ‘yes’ or ‘no.’ The whole system tends to grind down to a very slow crawl."

The vetting process varies in the Obama White House, but it typically begins with a brief conversation with a lawyer from the White House counsel’s office on basic questions: drug use, taxes, criminal convictions. Next are financial disclosure forms seeking information about transactions as far back as a decade: home purchases, investments, income, employment. That is followed by questions from the Office of Government Ethics, which scours the answers for inconsistencies.

In the security check that follows, potential nominees are asked to disclose all travel and meetings with foreign governments during the past 10 years or more. That is followed by a request for everything the nominee has ever written — papers, speeches, articles — and the official questions from members of Congress.

"The basic premise was that it was better to over-vet, to get everything on the table early and not give something that could end up becoming a scandal," said one former administration official, who underwent his own examination and requested anonymity to discuss internal White House procedures.

At the State Department, which has one of the emptiest high commands, the top official for arms control is waiting for Senate confirmation, and there is no permanent ambassador at large for global women’s issues. Kerry is also missing one of his two primary deputies. White House officials say that the vacancies are the result of departures that came about when Hillary Rodham Clinton left the top post after the November election. Several came open just a few weeks ago.

The Commerce Department vacancies have emerged since John E. Bryson abruptly left the secretary’s post last June after an accident in which he had a seizure while driving.

Wolf, the Virginia Republican, who has long focused attention on the war in Darfur, said the lack of a top State Department official for Africa meant that "you don’t have the decision makers there." And in a letter to Rebecca M. Blank, the deputy commerce secretary, he wrote that he was also concerned about the vacancies in her department.

"I urge you to prompt the White House to expeditiously appoint persons to these important positions," Wolf wrote. In thick black ink, he underlined the words "prompt" and "expeditiously," and added "This is important" under his signature.

William A. Galston, a senior fellow at the Brookings Institution who was a co-author of an article titled "A Half-Empty Government Can’t Govern," said he was especially taken aback by the vacancies at the State Department.

"John Kerry won’t be able to function very long as his own assistant secretary for the Near East," he said.