I am quite sure that all of our American readers and many others besides will be familiar with this choice bit of visual history, executed by James Montgomery Flagg:

Uncle Sam Wants...well, you know

Though perhaps you didn’t know that the same artist produced this image:

join the army -- get skewered by a naked swordswoman!

Now de gustibus non est disputandum of course, but if you really wanted to get me to show up at a recruiting post, I think I know which martial image I would use.