What ended and broke the stalemate on the Western Front in World War 1?
During the time 1917-1918 the stalemate on the western front, which had lasted for almost three and a half years, was broken. The four main reasons for this break were the US entry into the war after the sinking of the passenger ship the RMS Lusitania carrying hundreds of Americans by a German U-boat, the German plan of attack called the ludendorff offensive and its failure, the British blockade of German ports and the new technology that was developed and used during the war.
