How did trench war fare affect war?

The extremely costly and bloody war of attrition caused by strongly fortified trenches on the western front, prompted the British to find a suitable answer to break the stalemate without suffering horrendous casualties. The concept of a armored vehicle that could upset the stalemate arose. Code named "tanks" they were initially used to support infantry maneuvers and provide infantry some cover. These initial tanks were slow, clumsy and poorly armored. The psychological effect of these tanks were actually a drawback, The Defending troops were terrified of these large lumbering walls of metal and these tanks soaked up firepower and became deathtraps. Through trial and error, early commanders eventually learned what these tanks were capable of. Eventually instead of tanks supporting the infantry, the tanks all came at once to maximize the shock effect of armor. Light, fast tanks in large waves minimized the effect of artillery and antitank guns. These maneuvers leave gaps in the enemy trenches, which the infantry could then exploit. In WW1, tank warfare was attempted as a response to trench warfare, but there were many problems as mentioned above. Toward the end of the war, British tanks were fitted with a device called a fascine (basically a bundle of lumber) which could be dumped into a trench, forming a bridge with which the tank could cross over. The first APC (Armored Personnel Carrier) was also used in WW1, the "Pig," a modified British tank with weapons removed and two large Navy-type doors on either side. As mentioned above, Plan 1919 of General JC Fuller called for fast and lightly-armed tanks (Whippets) to exploit the breach. The war ended before it could be implemented, but it was the forerunner of General Heinz Guderian and the German Blitzkrieg of 1939-40