Boards have been steadily reinforcing their ranks through the addition of more directors with military experience in recent years.

Veterans can add leadership and strategic perspectives, but also tactical skills, such as cybersecurity expertise, sources said. Boards with military experience are also known to hold CEOs to account more effectively than those made up entirely of civilians, research shows.

These directors come from every branch of the military and have served in a range of conflicts — including a handful of sitting directors who even served in World War II. And they are more prevalent now than 10 years ago.

In 2015, there were 293 directors with military experience on the boards of Russell 3000 companies, according to data from public company intelligence provider MyLogIQ, which reviewed proxy statements to collate the data. A decade later, that number was 569.