Methuen Treaty ensure full allied commitment to the war in Spain. The second treaty, signed 27 December 1703 (popularly known as the "Port Wine Treaty") helped to establish trading relations between England and Portugal. The terms of it allowed English woollen cloth to be admitted into Portugal free of duty; in return, Portuguese wines imported into England would be subject to a third less duty than wines imported from France. This was particularly important in helping the development of the port industry. As England was at war with France, it became increasingly difficult to acquire wine, and so port started to become
Secret treaty financial arrangements, and 'military understandings'" are commonly cited as one of the causes of World War I. For example, the Reinsurance Treaty of June 1887 between the German Empire and the Russian Empire (negotiated by German Chancellor Otto von Bismarck in order for Germany to avoid a two-front war), was a "highly secret treaty" in which the two powers pledged a three-year period to remain neutral should the other become involved in a war with a third country, unless Germany attacked Russia's longstanding ally France or Russia attacked Germany's longstanding ally Austria-Hungary. The use of "secret agreements and undertakings between