Ms. Young’s credentials as an objective observer, however, were undermined by the fact that she posted a snapshot of herself with Lieutenant Dratwa on Twitter two hours before she defended him. She also works with the pro-Israel advocacy group Stand With Us.

A second screenshot of the image on the officer’s Facebook page, posted on the American blog Your Black World under the headline, “Israeli Army’s Social Media Director Poses as Obama in Blackface,” showed some of the replies it garnered when Lieutenant Dratwa first uploaded it in late September.

Among the positive responses was one from David Saranga, an Israeli diplomat who seemed to signal his approval of the joke with a smiley face emoticon and a lighthearted reply. Mr. Saranga also teaches the use of viral marketing techniques at Israel’s Asper Institute for New Media Diplomacy at the Interdisciplinary Center in Herzliya. According to the part of his Facebook profile that is still public, Lieutenant Dratwa is a graduate of the center who was working last year on a Web site, nocamels.com, set up by the Asper Institute.

Mr. Saranga, as The Lede reported last year, was one of the first Israeli officials to help publicize a hoax in which an actor pretending to be a liberal Israeli video blogger recounted what turned out to be a fictional encounter with the organizers of the Gaza flotilla movement. He did not reply to a request for comment on Monday.

Although Israeli soldiers are not supposed to express political opinions, Lieutenant Dratwa’s other social media accounts offer clues as to his ideological leanings. The most recent post on his personal blog, written in October, explained his view that Mitt Romney was likely to win the American presidential election. Barack Obama “sold a dream” in 2008, Lieutenant Dratwa wrote. “But with dreams no one can fill his fridge or feed his children.” He added: “Americans today need a father who is able to lead the country with a strong hand, not a dreamer.”

Several of the officer’s older blog posts appear to have been removed from his site, including one featuring a video described as a “comic caricature of Islam,” and another that recounted “the true story of an arrest in the Palestinian territories.”

Lieutenant Dratwa’s YouTube channel includes video of Geert Wilders, the anti-immigrant Dutch politician, praising Israelis for “defending their country against the Islamic jihad,” in an interview with the far-right, Islamophobic German site Politically Incorrect. “Their fight is our fight,” Mr. Wilders told the German site, “so at the end of the day, we are all Israel.” As The Ledeexplained in 2010, Mr. Wilders expressed strong support for Israeli settlements built on West Bank land occupied militarily since 1967 during a visit to Tel Aviv that year.

Another clip on Lieutenant Dratwa’s YouTube channel is a satirical sketch mocking pro-Palestinian activists produced by Latma, a group of conservative Israeli comedians who mock liberal attitudes. One Latma sketch produced in 2010 was a fake news report on “Kazabubu the Jewish Cannibal,” an African tribesman who claimed to be Jewish, played by an actor in blackface.

It remains unclear what the substance on Lieutenant Dratwa’s face was, but one quirk of the @IDFSpokesperson Twitter account under his control is that it so often draws attention to photographs of female Israeli soldiers applying mud or camouflage paint to their faces. Apparently part of a continuing campaign to soften the image of the Israeli Army by showing smiling women in its ranks, the I.D.F. Photo of the Day features such images again and again.

Strangely, Lieutenant Dratwa appears to have been well aware of the risks inherent in using Facebook to document one’s own life. In a comment posted on the Web site of France 24 three years ago, he wrote:

Facebook is basically an enormous avenue on which every user opens a shop with a window display on their private life. With all the information you upload onto the platform — photos, interests, occupation, hobbies, favourite books, films and music, marital status, political leanings, dress sense — you’re handing over your electronic DNA….

We no longer have a private life. We’ve reached a stage where our bosses can find out what we do at home, where our children can follow our adult relationships, our colleagues can spy on us and advertisers can find out exactly what makes us tick. We’ve lost our freedom and the ability to do the things we like without anybody’s knowing about it.