Using government or military imagery in your film in the United States has specific legal implications. Here are key considerations:

Public domain:  Many government-created works, including imagery, are in the public domain and can be used without permission. However, this does not apply to all materials, especially those created by contractors or private entities working for the government.

Trademarks and logos: Military insignias, logos, and emblems are often trademarked. Unauthorized use of these can lead to trademark infringement claims. You may need explicit permission from the relevant government agency.

Accuracy and permissions : If your film portrays military operations or uses government imagery in a way that implies endorsement or collaboration, you must seek approval from agencies like the Department of Defense ( DoD ). The DoD has strict guidelines for granting permissions. 

Defamation and misrepresentation: Misrepresenting government or military actions could expose you to defamation claims or reputational risks.

National security concerns: Using classified or sensitive material without authorization is illegal and can result in severe penalties.

To mitigate risks, consult an entertainment lawyer to ensure compliance with copyright, trademark, and other legal requirements related to government or military imagery.