Amidst spiraling deficits and scandals such as those involving Solyndra and Fast and Furious, it is sometimes easy to forget what the United States is capable of achieving. This is something that repeatedly struck me during a recent week-long trip to Afghanistan with other national-security experts at the invitation of International Security Assistance Force commander Gen. John Allen.

In late October, as we witnessed a medal-pinning ceremony under a clear blue sky in a desolate corner of Kandahar Province, just miles from Taliban leader Mullah Omar’s hometown, it was impossible not to be amazed at what America’s men and women in …