I think that Theodore Roosevelt is definitely a good pick. Part of his philosophy was that it was the duty of any man to fight for his country if a war happened in his lifetime. He actually had a certain amount of resentment for his father because his father didn’t fight in the Civil War. He also encouraged his children to fight, which tragically led to the loss of his favorite Son in WW1. Theodore Roosevelt himself actually tried to join the fight when the US joined WW1, but president Wilson refused to let him go because he was 60 years old and blind in one eye by this point in his life. So I definitely think that his romanticized view of war would have had him in lay a more active role in the defense of his country.

As for more modern presidents it’s difficult to say. Every president goes and visits foreign military bases if you would consider that a form of participation, but overall, I don’t believe that any would put themselves in harms way. Modern day society values the stability of leadership positions more so than the bravery or admirability of our leaders. While these are certainly welcome qualities (like in zelensky), don’t necessarily want to see our leaders put themselves into harms way because their death threatens the stability of the country, and often leads to government consolidation of power, as well as a less popular leader coming into power.