battleships. The battle of Jutland (May 31/June 1, 1916) saw the main German High Seas Fleet engage in a monumental yet inconclusive clash with the far stronger Grand Fleet of the Royal Navy. Arguing this battle proved the validity of Mahanian doctrine, the navalists took control in the Senate, broke the House coalition, and authorized a rapid three-year buildup of all classes of warships. A new weapons system, naval aviation, received $3.5 million, and the government was authorized to build its own armor-plate factory. The very weakness of American military power encouraged the German Empire to start its unrestricted submarine attacks in 1917. It knew this meant war with America, but it could discount the immediate risk because the U.S. Army was negligible and the new warships would not be at sea until 1919 by which time the war would be over, Berlin thought, with the German Empire victorious. The notion that armaments led to war was turned on its head: refusal to arm in 1916 led to war in 1917. War declared In January 1917, the German Empire resumed unrestricted submarine warfare in hopes of forcing Britain to begin peace talks. The German Foreign minister, Arthur Zimmermann invited revolution-torn Mexico to join the war as the German Empire's ally against the United States if the United States declared war on the German Empire in the Zimmermann Telegram. In return, the Germans would send Mexico money and help it recover the territories of Texas, New Mexico and Arizona that Mexico lost during the Mexican–American War 70 years earlier. British intelligence intercepted the telegram and passed the information on to Washington. Wilson released the Zimmerman note to the public and Americans saw it as a casus belli—a justification for war. At first, Wilson tried to maintain neutrality while fighting off the submarines by arming American merchant ships with guns powerful enough to sink German submarines on the surface (but useless when the U-boats were under water). After submarines sank seven U.S. merchant ships, Wilson finally went to Congress calling for a declaration of war on the German Empire, which Congress voted on April 6, 1917. As a result of the Russian February Revolution in 1917, the Tsar abdicated and was replaced by a Russian Provisional Government. This helped overcome Wilson's reluctance to having the U.S. fight alongside a country ruled by an absolutist monarch. Pleased by the Provisional Government's pro-war stance,