One of the most provocative comments from Abe allies came this month, when an ultraconservative novelist, Naoki Hyakuta, who was appointed by the prime minister himself to the governing board of public broadcaster NHK, said in a speech that the Tokyo war tribunal after World War II was a means to cover up the “genocide” of American air raids on Tokyo and the atomic bombings of Hiroshima and Nagasaki. The United States Embassy called the comments “preposterous.”

Mr. Hyakuta’s comments came days after the new president of NHK, who was chosen last month by a governing board including Abe appointees, raised eyebrows in Washington by saying that Japan should not be singled out for forcing women to provide sex to Japanese soldiers during the war, saying the United States military did the same. Most historians say the Japanese system of creating special brothels for the troops, then forcing tens of thousands of women from other countries to work there, was different from the practice by other countries’ troops in occupied areas who frequented local brothels.

The Japanese discontent with treatment by the Obama administration goes back to early last year, when a newly elected Mr. Abe tried to arrange an immediate trip to meet the president, only to be told to wait a month. More recently, Japanese officials have appeared hurt that Mr. Obama wants to spend only one night in Japan during a visit to the region in April.

Some analysts say this feeling of being held at arm’s length may be driving some of the recent criticisms of the United States.

“This is one of the most dangerous moments in U.S.-Japan relations that I have seen,” said Takashi Kawakami, an expert on international relations at Takushoku University in Tokyo. “Japan is feeling isolated, and some Japanese people are starting to think Japan must stand up for itself, including toward the United States.”

Analysts note that many of the comments are being made by relatively minor figures, and not members of Mr. Abe’s cabinet. They also say that Japanese public attitudes remain overwhelmingly favorable toward the United States, which has been the guarantor of Japan’s postwar security with its 50,000 military personnel stationed in the country.

At the same time, the analysts say, frustrations on both sides are real. In the United States, they reflect an ambivalence toward Mr. Abe, as some worry that he is returning to the agenda he pursued the last time he was prime minister — trying to revise the country’s pacifist Constitution and downplay wartime atrocities in the name of restoring lost national pride.