It seems like it was gradually escalated on both sides to me. > When Britain joined the war on August 4, 1914, they did not immediately execute the entire plan

It seems like it was gradually escalated on both sides to me. > When Britain joined the war on August 4, 1914, they did not immediately execute the entire plan to blockade all German imports. It was not until nearly four months into the war that Britain labeled the North Sea a war zone, and also began directing limited forces in the Mediterranean as well to restrict all German trade routes. > The final shift to establishing the full blockade came on November 11, 1914, after several German light cruisers were observed attempting to lay mines off the coast of southern England. This act of aggression gave British leaders the impetus they needed to declare the full blockade without U.S. resistance because during the first four months of the war, Britain had confined itself to blocking only war materials from reaching German ports. World opinion of Germany during this time began to deteriorate because of repeated reports of brutality directed against Belgian and French civilians. These things have a way of "tit for tat" escalating. If your opponent is doing things like executing whole villages of Belgian civilians as at louvain (August 1914), then the blockade starts to seem like a moral imperative. As well as that - if Germany is laying mines in layers off the British coast, that is a pretty effective way of stopping merchant traffic to Britain and is sure to elicit a response in kind. If a country started laying mines off the coast of New York how do you think the US would respond? http://www.inquiriesjournal.com/articles/899/2/the-british-blockade-during-world-war-i-the-weapon-of-deprivation http://www.inquiriesjournal.com/articles/899/2/the-british-b...