I think this is clearly an anti-war song.
Kids looking down while the army marches, gunfire and destruction around them, while they are kept away from it all in castles in the air (= dreams/plans that are unlikely to happen). The king (= political elite) doesn't care if kids (= pureness, good nature) cry out; the king also cries out, but shouting lies. If kids were to choose who would lead them, the king wouldn't certainly be their leader; instead, it would be an ordinary person.
I think this is clearly an anti-war song. Kids looking down while the army marches, gunfire and destruction around them, while they are kept away from it all in castles in the air (= dreams/plans that are unlikely to happen). The king (= political elite) doesn't care if kids (= pureness, good nature) cry out; the king also cries out, but shouting lies. If kids were to choose who would lead them, the king wouldn't certainly be their leader; instead, it would be an ordinary person.