Not much has been written about this song, which focuses on facing an apocalyptic future, and might also be implying something about the self-fulfilment of prophecy. The song was written at the time of the Cold War and many thought that a nuclear holocaust was on the verge to happen. Although the world's political situation has changed since and that the threat of a global conflict between the USA and the USSR (and their respective allied nations) has gone away, many governments still play the card of fear to get their ways, "international terrorism" being the new enemy (this reminds me of George Orwell's 1984 where the enemy is never the same, but there is always one to fuel the people's fears).
Nothing has changed, and the advice given in the song to "die with your boots on" is also still valid. It is not advocating an armed struggle, but more probably the resistance to this fear that the leaders of the planet are using so well to control the masses. After all, people in fear cannot think straight and see what their governments are really like!
The Frenchman mentioned in the second verse is most likely Michel de Notre-Dame (15031566), otherwise known as Nostradamus. His prophecies are always referred to whenever a major sinister event occurs, and the wackiest interpretations appear, doubling the fear of the actual or potential danger to that of esoterism and the occult.
Anyway, "Die With Your Boots On" may not be the best song on the album, but it isn't bad either. Like many Maiden songs, it is more enjoyable when played live than on the studio album.
Adrian and Bruce came up with the main riff. Bruce came up with the lyrics. I came up with the chord sequence behind the verse and the cross section that goes into the main chorus. This is another personal favourite of mine. It has more chords than riffs, which I suppose might make it strange as to why I really like it so much. It's a very powerful number live. I get off on the aggression of it.