What battle strategies did each side employ in the First World War 1? how effective were these strategies?U.S. history

The main military strategies at the beginning of the war were quite different from what happened as the war went on.  No one intended for the war to last very long, and so the strategies at the beginning were short sighted in many respects.  Later, strategy and tactics both became direct and wasteful.

The German strategy was the Schlieffen Plan, which called for a wide enveloping move with massed troops (including reserves) to overwhelm the French forces by descending upon their rear and threatening Paris.  The drawback of this plan was that by violating the neutrality of Belgium, Britain would be drawn in as an antagonist.

The French strategy was Plan 17.  It called for a direct offensive into the Ruhr Valley, a task beyond the capability of the French army given the tactics and equipment of the German forces.  This also opened up the French to the crushing mass of German troops which the Schlieffen Plan called for.  The saving grace for France was that the Belgians resisted the German invasion and the British filled in the gap on the north side of the French lines.  The British army was massively outnumbered, but by a hasty retreat followed by a daring push forward into the gap between the German 6th and 7th Armies the British induced the Germans to retreat at the critical moment of the First Battle of the Marne.

The real problem on the Western Front began then.  No plan had worked, therefore the war was not decided by a short series of battles.  No one knew what to do next, so both sides engaged in flanking attacks and blocking them, until the lines reached from the Swiss border to the English Channel.  At that point both strategy and tactics became pointless.  Periodically one army or another would mount an offensive, which meant heavy artillery bombardment followed by masses of infantry (and later infantry and tank attacks).  These offensives produced incredible casualty rates, but no progress toward a military solution.

There were of course also plans made before the war by the other major powers, but they were all equally out of touch with the reality of modern war and economics.  No one had believed the economic power of European nations could sustain a major war for long, because of the interdependance of modern economies.  Unfortunately, they were wrong.  Battle plans became nothing more than plans for wasting hundreds of thousands of lives.  Even the amphibious landings on Gallipoli simply did not take effective account of modern weaponry.

The Ludendorff offensives, which the Germans hung all their hopes on in 1918, showed promise with infiltration tactics by storm troops, but the effect of initial breakthroughs on commanders was always to push on, even after resistance hardened.  The only strategies which worked were political.  The most important was that the British managed to keep the United States from opposing their blockade of both war materials and materiel bound for Germany, even if on neutral ships and bound initially for neutral harbors.  Since the two countries went to war in 1812 over the same principle, this was a major coup.

The British blockade starved Germany and Austria-Hungary, and this was followed by diplomatic pressures which eventually brought the US into the war.  Their manpower and manufacturing ability was simply too much for the Germans to continue to fight against.