An internal Pentagon email has outlined potential punitive measures against NATO allies that U.S. officials believe have failed to adequately support American operations, according to a source familiar with the communications.

The email reportedly suggested suspending Spain from NATO among other possible actions, though the specific circumstances and timeline of these proposals remain unclear. The communications appear to be related to disagreements over allied support for U.S. positions on Iran-related matters.

The revelations come as European Union nations are examining their own mutual defense obligations outside the NATO framework. The EU has a lesser-known collective defense clause that requires member states to provide aid and assistance to any member facing armed aggression on its territory.

However, security experts emphasize that the EU's mutual defense provisions are not intended as a replacement for NATO's Article 5 collective defense guarantee, which has been the cornerstone of transatlantic security since the alliance's formation in 1949.

The Pentagon has not officially confirmed the existence or content of the reported internal communications. NATO officials have also not commented on any potential changes to member status or alliance procedures.

The reported tensions highlight ongoing challenges in maintaining alliance cohesion as member nations balance domestic priorities with collective security commitments and U.S. foreign policy objectives.