6 outstanding questions about the Bowe Bergdahl prisoner swap

More than a week and a half after Sgt. Bowe Bergdahl was returned from Taliban captivity in exchange for five Taliban-affiliated detainees at Guantanamo Bay, a number of outstanding questions continue to swirl around the controversial prisoner swap.

The administration answered at least some of those questions on Wednesday, providing additional information on Bergdahl's background and his condition in captivity.

A coast guard official confirmed to CBS News that Bergdahl served a brief stint in the Coast Guard before joining the Army. He joined in 2006 and was discharged just 26 days later.

Army Lt. Col. Elaine Conway confirmed that the Army is aware of Bergdahl's discharge, but when asked whether it was known at the time of his enlistment, and whether he received a waiver, a spokesperson said the army was "looking into it." The reasons for Bergdahl's departure from the Coast Guard are still unclear.

And during testimony Wednesday before the House Armed Services Committee, Defense Secretary Chuck Hagel continued pushing back at critics of the prisoner swap, saying the U.S. was taking its "last, best" opportunity to secure Bergdahl's return.

The Pentagon chief said Bergdahl was in deteriorating health when the exchange was made. Hagel also defended the decision to not notify Congress beforehand, saying concerns about Bergdahl's safety compelled the administration to keep the affair as covert as possible.

"We grew increasingly concerned that any delay, or any leaks, could derail the deal and further endanger Sgt. Bergdahl," Hagel said.

Despite the trickle of information, critics continue to raise concerns. Some wonder what the swap says about the future of other Guantanamo inmates and whether the U.S. can keep tabs on the five released detainees, who currently reside in Qatar.

Others have wondered how the exchange will impact the U.S. policy barring negotiations with terrorists, and whether it could presage broader negotiations with the Taliban.

CBS News Senior National Security Analyst Juan Zarate, a deputy national security adviser to former President George W. Bush, identified six questions that remain unanswered about the negotiations surrounding Bergdahl's swap -- and some of the thorny issues the exchange could raise going forward.

Was there money involved?

Beyond the swap of the individuals involved, Zarate said, there remain questions about the terms of the deal itself.

"There are still questions as to whether or not money exchanged hands," he explained. "For example, did the Qatari government provide financial support, for example, to the Haqqani network, which had a hand in holding Bergdahl? Who's supporting the Taliban members who've returned to Qatar? Who's supporting their families?"

Was this really our last chance to return Bergdahl?

"The administration has said this was the last, best opportunity," Zarate said, but "there have to be questions then about whether or not other options were available."

"For example," he said, "working with the Pakistani government to pressure the Taliban...to be able to return Bergdahl. Or rescue missions, as we've seen in the past -- were those a possibility? So those questions will emerge as well."

Is the swap a preview of broader Taliban negotiations?

As the U.S. prepares to remove nearly all of its troops from Afghanistan by the end of the year, "there are also questions about whether or not [the Bergdahl swap] is intended as a step to begin negotiations with the Taliban in some way," Zarate said.

"I don't think so," he added, "but there really is a question about the next step with the Taliban, given it appears we've begun to legitimate them a little bit and we've signaled that political reconciliation is necessary for the future of Afghanistan. So was this part of that thinking?"

We negotiated with terrorists -- could that do us harm?

"The United States government has the principle, obviously, of leaving no soldier behind," Zarate said. "But we also have a policy and principle of offering no concessions to hostage takers. And in offering five very high-value individuals in return for an American soldier, we have violated that principle."

"Acknowledging that is important," Zarate said, wondering whether the policy against negotiating with terrorists was part of the discussion surrounding Bergdahl's release. He also questioned whether other cases of Americans being held around the world were impacted by the swap.

What is the fate of the other Guantanamo detainees?

The swap also raises questions about what the administration plans to do with the other 149 detainees still at the U.S. facility in Guantanamo Bay, Cuba, Zarate said. "Does the administration see this as an opening stage of a more aggressive push to empty Guantanamo of some of the detainees?" he asked. "The argument being, perhaps, not only are we ending the war in Afghanistan, but we're willing to take the risk of returning some individuals."

"If we're willing to live with the risk of returning five high-level Taliban members, perhaps we can live with the risk of less dangerous, less risky individuals leaving Guantanamo and going back around the world," Zarate said.

Is this what the end of the "war on terror" looks like? And is it premature?

Zarate also wondered whether the Bergdahl swap was part of a broader pivot by the administration to signal an end to the war on terror. "Is the administration, in furtherance of the narrative and the policy of ending the wars, planning any other steps like this?" he asked. "Are there things being done with respect to Guantanamo, with respect to placement of troops, with respect to deals being made around the world that are posturing us to demonstrate that there's an end to our wartime footing?"

Zarate worried that the pivot might be dangerous "at a time when the war has metastasized and we're seeing threats around the world grow more dangerous."