Because a German submarine was responsible for the sinking of the Luisitania, with many American citizens on board.
German u boats were attacking civilian ships. Many US trade ships, and civilian transport ships were attacked. when the USS lusitania sunk and 100 US citizens died, the US declared war on Germany becuz of Germany's unrestricted submarine warfare
Airmobile warfare: the helicopter
Pearl Harbor push the US into the war against the axis powers
The US revolutionary war
In warfare the war which is most costly to US lives is the US Civil War.
unrestricted submarine warfare
yes
civil war
Converted the guerrilla war in Vietnam into a conventional one; and started open warfare between North Vietnam & America.
throughout most of the war, they mainly employed guerilla tactics, however, in the push to saigon, conventional warfare was adopted as the main military strategy among the NVA, but the viet cong largely maintained their use of guerilla warfare
Un-restricted submarine warfare
Shortly after DS, the US military had a tough time trying to convince the US population that war is really a violent thing; and that it was NOT A VIDEO GAME, nor a push button game. DS appeared to be nothing but smart weapons, cruise missiles, robot airplanes, and all appearing on live video. The US military did NOT want people to enjoy war. The US military wanted people to take it seriously and avoid war. But, video games and push button warfare are tough opponents to defeat!