LAST month Pfc. Bradley Manning pleaded guilty to several offenses related to leaking hundreds of thousands of documents to WikiLeaks in 2010, a plea that could land him in jail for 20 years. But Private Manning still faces trial on the most serious charges, including the potential capital offense of “aiding the enemy” — though the prosecution is not seeking the death penalty in this case, “only” a life sentence.

If successful, the prosecution will establish a chilling precedent: national security leaks may subject the leakers to a capital prosecution or at least life imprisonment. Anyone who holds freedom of the press dear should shudder at the threat that the prosecution’s theory presents to journalists, their sources and the public that relies on them.

You don’t have to think that WikiLeaks is the future of media, or Private Manning a paragon of heroic whistle-blowing, to understand the threat. Indeed, the two of us deeply disagree with each other about how to assess Private Manning’s conduct and WikiLeaks’s behavior.

Mr. Abrams, who represented The New York Times in the Pentagon Papers case, has argued that both Daniel Ellsberg, who provided the documents to the newspaper, and The Times acted with far more restraint and responsibility than Private Manning and WikiLeaks have, and that both have repeatedly behaved with a devil-may-care obliviousness to genuine national security interests.