The ranking Republican on the Senate Armed Services Committee on Thursday accused the Obama administration of covering up the true nature of last year’s fatal attack on the U.S. consulate in Benghazi, Libya, amplifying yet another political proxy battle between the White House and Republicans.

James M. Inhofe of Oklahoma said his panel would focus on the military’s response to the assault. But, he said, “as bad as everything that I’ve stated is, what I think is worse is the cover-up.”

“It was obvious from the information we had on Sept. 11 that the second wave … of attacks on the annex was unequivocally a terrorist attack, and we knew it right at the time,” he said, accusing the U.S. ambassador to the United Nations, Susan E. Rice, of lying to the American people.

Inhofe’s comments — along with Sen. John McCain, R-Ariz., accusing the nation’s top military officer of making false statements —represented the latest escalation of charges surrounding the attack that left four Americans dead, including the U.S. ambassador to Libya. GOP lawmakers warned their probing of the Benghazi imbroglio would not soon end.

Armed Services Chairman Carl Levin, D-Mich., pushed back against the GOP’s criticism, saying the emphasis on the dissemination of information after the attack was, while relevant, not as relevant as understanding why the attacks occurred, bringing the attackers to justice and preventing further attacks.

Levin said during a hearing on the attacks with Defense Secretary Leon E. Panetta and the chairman of the Joint Chiefs of Staff, Gen. Martin E. Dempsey, that the committee would carefully oversee the use of U.S. Marines in protecting diplomatic missions.

“Unfortunately, to date, much of the discourse about the events surrounding the deadly attack against our facilities in Benghazi have focused on the preparation and dissemination of unclassified talking points that were prepared — at the request of Congress — by our nation’s intelligence professionals and approved by their most senior leadership,” Levin said.

Undeterred, Inhofe repeated his criticism of Rice who, on the Sunday talk shows after the attacks, described information provided to her by the U.S. intelligence community.

“Despite this clear evidence, it took this administration over a week to publicly admit what many of us already knew — that it was a terrorist attack, not simply a protest that turned violent as Ambassador Susan Rice adamantly and incorrectly insisted,” Inhofe said, adding that the attack called into question the entire U.S. military strategy in North Africa.

Inhofe noted that there were several attacks in the region against U.S., U.N. and British assets leading up to the attack in Benghazi.

He said the administration needed to explain why the Pentagon was not adequately positioned to address the threats, particularly on the anniversary of the Sept. 11 attacks.

An independent State Department accountability board found the military response was timely and appropriate but that there simply was not enough time, given the speed and intensity of the attacks, for the military to have affected the outcome, according to Panetta in testimony.

“The board found no evidence of any undue delays in decision-making or denial of support from Washington or from the military combatant commanders,” Panetta said in prepared remarks. To the contrary, the report found exceptional government coordination in evacuating U.S. personnel within 12 hours of the initial attack.

McCain said he was astonished to hear Panetta and Dempsey describe the military response as appropriately responsive. He noted that the United States has a military facility in Crete, slightly more than an hour flight from Benghazi, and that there had been warnings ahead of time that the consulate in Benghazi was in danger.

“Our posture was not there because we didn’t take into account the threats to our consulate,” McCain charged in a terse back-and-forth with Dempsey, who said he stands behind the assessment board’s findings and his statements. “So for you to testify to this committee that they were consistent with available threat assessments was simply false. What would have been an inappropriate response?”

McCain blamed the response on the Obama administration’s policy of a light U.S. footprint in Libya, a policy he argued against at the time.

“I stand by my testimony, your disputes notwithstanding,” Dempsey said. “We based our response on the combined effects on what we get from intelligence community, as well as what we get from the State Department and chief of mission.”

Sen. Saxby Chambliss, R-Ga., said he believed Dempsey’s response to the security warnings was disturbing and inadequate.

Dempsey said there were similar threats in other locations, such as in Yemen, and that Army Gen. Carter Ham, chief of U.S. Africa Command, had sought more security for Benghazi but was told there was no need. Asked who had determined that bolstering security was unnecessary, Dempsey said he did not know.

Nonetheless, Panetta said several lessons were learned from the attacks. First, more focus must be placed on the host nation’s capacity to defend U.S. facilities. Panetta said that, as a result, the United States would work with host nations to help provide security. In the meantime, the Pentagon has agreed to add 35 new security detachments over the next two to three years. There are 152 detachments currently.

Further, the Marine Corps’ security detachments will expand their roles beyond protection of classified information.

“This could include expanded use of non-lethal weapons and additional training and equipment, to support the Embassy Regional Security Officer’s response options when host nation security force capabilities are at risk of being overwhelmed,” Panetta said.

Panetta said intelligence gathering would have to be intensified.

“We have forces on alert and prepared to move, but our ability to identify threats, adjust posture, prevent plots and respond to attacks to our personnel at home and overseas depends on actionable intelligence,” he said.

As a result, there will be greater efforts to link intelligence with military posture and planning, he said. But Panetta also said the military should not and cannot be an emergency response force anywhere in the world, saying action depends on actionable intelligence.

Most important, Panetta said that while the Pentagon’s response was not tardy, there is a concern about ensuring the military has the resources to respond to such contingencies. Panetta then emphasized, as he has for two years, the need to avert across-the-board cuts, mandated in the deficit control law (PL 112-25) that he argues would undermine national security.