Earlier administrations have fired and prosecuted government officials who provided classified information to the media.
They have also tried to force reporters to identify their sources.
But the Bush administration is exploring a more radical measure to protect information it says is vital to national security: the criminal prosecution of reporters under the espionage laws.
Such an approach would signal a thorough revision of the informal rules of engagement that have governed the relationship between the media and the government for many decades.
Leaking information in Washington is commonplace and typically entails tolerable risks for government officials and, at worst, the possibility of subpoenas to journalists by prosecutors seeking the identities of sources.
But the Bush administration is putting pressure on the media as never before, and it is operating in a judicial climate that seems increasingly receptive to constraints on journalists.
It is not easy to gauge whether the administration will move beyond these efforts to criminal prosecutions of reporters.
In public statements and court papers, administration officials have said the law allows such prosecutions and that they will use their prosecutorial discretion in this area judiciously. But there is no indication that a decision to begin such a prosecution has been made.
Such prosecutions of reporters in the United States are unprecedented. But legal experts say that existing laws may well allow holding journalists accountable for crimes. Should the administration pursue the matter, these experts say, it could gain a tool that would thoroughly alter the balance of power between the government and the media.
The administration and its allies say that all avenues must be explored to ensure that vital national security information does not fall into the hands of the nation’s enemies.