Martial, warlike, military carry as their basic meaning belonging to, suitable to, or characteristic of war.
Martial distinctively implies reference to war in general and to its essential and fundamental characteristics; it often specifically suggests the pomp and circumstance of war.
Warlike, as a rule, implies reference to war as a reality, its actual causes, its actual methods, its actual effects; it therefore applies more often to feelings, acts, or activities that lead to or accompany real war than to those which suggest its thrilling or stirring qualities; thus, a warlike temper suggests bellicosity or readiness to fight to the bitter end, whereas a martial temperament suggests qualities (as dauntlessness, spiritedness, and eagerness) that bespeak one likely to behave well and valiantly in war.
Military is the broadest of these terms since it may imply reference to war, to arms, or to armed forces or might.
Sometimes military in reference to armed forces is specifically opposed to civil or civilian or it may be restricted to land, or land and air, forces and is then opposed to naval.