First, swapping Bergdahl for illegal enemy combatants (terrorists, in common parlance) signaled unmistakably to Taliban and al Qaeda that Obama is determined to withdraw from Afghanistan no matter what the cost to the United States or those in Afghanistan fighting to remain free.
Just days earlier, during his West Point graduation speech, Obama had again stressed that, no matter what the facts are on the ground, US forces will leave Afghanistan by the end of 2016. If the terrorists still had even the slightest doubt that they needed only a minimal amount of patience to regain control in Kabul, Obama has done everything in his power to eliminate that.
He is surrendering in Afghanistan.
Second, it is despicable for an American president to equate a US service member with terrorist criminals such as those at Gitmo. This is the worst form of moral equivalence, the inexcusable mistake of equating two radically different kinds of people or policies.
In Cold War days, we were right to exchange spies with the Soviets, like for like. But to exchange soldiers for criminals as if they were fungible is moral equivalence that we should reject when the terrorists themselves offer it. For our own president to make that mistake is tragic.