Updated at 9:47 a.m. ET.
The U.S. Marine Corps has vowed a full investigation into video posted online which purportedly shows Marines urinating on the dead bodies of Taliban militants in Afghanistan.
CBS News national security correspondent David Martin says if it turns out to be authentic, those involved could face court martial proceedings for violating U.S. military rules which specifically forbid "photographing or filming... human casualties" - regardless of whether the Americans were actually urinating.
Martin says the U.S. military has told CBS News the Marines seen in the video are no longer in Afghanistan, raising a question about how old the clip may be.
Click the player above to see Martin's full report.
Regardless, the Pentagon is extremely worried about what reaction might be. The hope, Martin tells "CBS This Morning" co-anchor Charlie Rose, is that the Taliban's own unpopularity in Afghanistan will lead many in the country to see the video as an insult to the radical Islamic group, rather than to Afghan culture or Islam.
Afghan President Hamid Karzai, however, strongly condemned the video as "completely inhumane" and called on the U.S. to punish the Marines involved. The country's defense ministry called the video "shocking."
U.S. officials echoed that anger. Defense Secretary Leon Panetta said in a statement the actions depicted in the video were "utterly deplorable."
"This conduct is entirely inappropriate for members of the United States military and does not reflect the standards or values our armed forces are sworn to uphold. Those found to have engaged in such conduct will be held accountable to the fullest extent," he said.
The video was posted to YouTube by a user called "moviesoundtrackvideo" with the title "Marines urinating on dead soldiers Taliban," and while its authenticity has yet to be confirmed, Martin says the damage likely to be inflicted by the clip won't be curtailed quickly by the pledge of an investigation.
The veteran senator and former Vietnam war POW said the video shows "a handful of undisciplined young people, of the 100-some-thousand Marines we have. It makes me so sad."
McCain said the video would do "great damage" and urged a complete investigation, stressing that any U.S. service members found guilty "should be punished."
Eight years ago in Iraq, U.S. soldiers at Abu Ghraib prison posed next to detainees in degrading positions. After the photos surfaced, some American troops were dishonorably discharged; others were sentenced to military prison.
The video also comes to light as Afghanistan's leaders ratchet up pressure on the U.S. to hand over control of security and law enforcement duties more quickly.
On Saturday,that U.S. military personnel had abused prisoners at the main U.S.-run detention facility in the war-torn country, increasing their calls for the prison outside the Bagram Air Base to be turned over completely to domestic forces.
While the U.S.-led war in Afghanistan has left almost 2,000 Americans troops dead, many thousands more Afghan civilians have been killed in the violence during the last 10 years, and that bloodshed has led many Afghans to deeply resent the American presence.
Afghan citizens who spoke to the media Thursday reacted with predictable rage, showing that, as Martin predicted, the damage to America's image may already be done.
"We don't want them anymore on our soil, we don't like foreign soldiers to be on our soil," angry Kabul resident Feda Mohammed told the Reuters news agency. "They have to leave."
Another big question the scandal will raise in coming days is what effect it may have on the beginning of reconciliation talks between the Taliban and the U.S. government, which seem to be looming ever larger after the recent announcement of a new .
While both the Taliban and the U.S. government insist no direct peace talks have yet taken place, the two sides are, by all accounts, moving in that direction.
Speaking to CBS News' Ahmad Mukhtar on the phone Thursday, Afghan Taliban spokesman Zabihulla Mujahid strongly condemned the video. He reiterated that talks with the Americans have not begun, but he said if they do, the video of the alleged desecration "will not harm" the dialogue.