Anti-tank warfare arose as a result of the need to develop technology and tactics to destroy tanks during the First World War. Since the first tanks were developed by the allies in 1916 but not principally used till 1917 the first anti-tank weapon was developed by Germany. It was a scaled-up bolt-action rifle designated the Mauser Tank-Gewehr Model 1918 that fired a 13mm cartridge with a solid bullet that could penetrate the thin armor of tanks of the time and destroy the engine or ricochet inside killing occupants. Because tanks represent an enemy's greatest force projection (aside from nuclear artillery and tank vs. tank engagements), anti-tank warfare has been incorporated into the doctrine of nearly every combat service since. The predominant anti-tank weapons at the start of the Second World War were the tank-mounted gun, limbered (towed) anti-tank guns and anti-tank grenades used by the infantry as well as ground-attack aircraft such as the Junkers Ju 87 Stuka.