LEXINGTON, Kentucky -- "Joe Biden is one of the most experienced debaters we have in modern politics," Paul Ryan said before leaving his Florida debate camp for the site of Thursday's vice presidential debate.  "But the Achilles heel he has is President Obama's record."

In a series of events that could not have been predicted just a few weeks ago, the day before the VP debate saw a significant addition to President Obama's record.  A House committee heard extensive testimony establishing that the Obama administration refused requests for heightened security from ambassador to Libya Christopher Stevens and his aides, requests made just weeks before Stevens and three other Americans were murdered in a terrorist attack timed to coincide with the anniversary of September 11.  House testimony also established beyond any doubt that Obama, Secretary of State Hillary Rodham Clinton, White House spokesman Jay Carney, and UN Ambassador Susan Rice all made untrue statements when they attributed the attack to angry protests over an anti-Muslim video.

So what will Ryan say about President Obama's recent record on Libya?  "The term I would use is 'unraveling,' says a member of Team Ryan, referring not just to the Libya affair but to Obama's larger foreign policy.  "I would not at all be surprised if Congressman Ryan uses it."

But don't expect Ryan to get into the weeds of what happened in Libya.  "I don't know that it's worth litigating in detail some of what went wrong in Benghazi," the aide says, "but it does point to the broader issue of what's gone wrong with the president's foreign policy.  I don't think it serves us well to get into a back-and-forth of when this consular officer or that requested more security."

So don't look for details from Ryan on the Libyan security situation.  But there is also the issue of the administration's truthfulness, or lack of it, in its statements about the Benghazi violence.  "The president seemed reluctant to call it what it was, a terrorist attack on Americans," says the aide, "and without a reasonable explanation as to why it has taken them so long to admit what people on the ground knew at the time."

The aide's remarks suggest that Ryan will also tread lightly about the administration's false statements.  But it seems Ryan could at least be as tough as the Romney campaign itself.  On Wednesday, campaign policy director Lanhee Chen released a statement accusing the administration of misleading the public and continuing to make "incomplete and indirect responses to simple and straightforward questions."  While there are serious questions about the administration's security policies in Libya, Chen said, there is also the question of whether the administration "told the American people the whole truth in the aftermath of the attack."

Certainly Ryan can go that far in the debate.

The vice presidential showdown, the only debate between Ryan and Biden, will cover both foreign and domestic topics.  Moderator Martha Raddatz will have the final say, but Team Ryan expects a significant amount of time to be devoted to foreign policy.  They are mindful that even with recent events in Libya and elsewhere, the voters' top concern remains jobs and the economy.  But they know that Obama, especially after the May 2011 killing of Osama bin Laden, has enjoyed an advantage on the question of international affairs, filling the role of commander-in-chief, and fighting terrorism.  Part of Ryan's job will be to put a dent in that image of Obama as a strong national security leader

And Biden's, too.  "You could fill a bookshelf with the foreign policy mistakes that Vice President Biden has made in the course of his very long career in Washington," says the aide.  "But the focus has got to be on the top of the ticket, on the president's foreign policy record."

And that means talking about Libya.  Contrary to Team Ryan's apparent reluctance to "litigate in detail," it is usually the details of stories -- not a barrage of them, but a few effective illustrations -- that make an impression in viewers' minds.  Though much remains unknown about the Libyan debacle, it is known that Ambassador Stevens and his staff feared terrorist attacks and asked for more security; that the State Department denied those requests; and that after Stevens and three others were murdered the administration, from the president down, spread an untrue and misleading explanation for the attack.  Serious questions remain about the administration's behavior in the Libya episode, and a vice presidential debate seems as good a place as any to air some of them.