President-elect Donald Trump has tapped at least three retired generals to fill his administration’s top national-security positions.

He’s considering two others, Gen. David Petraeus and Navy Adm. James Stavridis, for the role of secretary of state.

And in the running for other high-level national-security positions have been the NSA director, Adm. Mike Rogers, as well as retired generals Jack Keane and Stanley McChrystal.

The nominees — retired Gen. James Mattis as defense secretary, retired Gen. John Kelly as homeland security secretary, and retired Lt. Gen. Michael Flynn as national security adviser — and potential nominees have sparked fears of a potential imbalance in civilian and military relations in a Trump administration.