Denmark-Norway's attempt to remain neutral in the struggle between France and the United Kingdom and their respective allies early in the 19th century came to an end after the United Kingdom's pre-emptive naval actions of 1807, in which the entire Danish fleet was captured, the British operating under the possibility that Denmark-Norway was planning to join the Napoleonic Wars on the side of the French. The British imposed a blockade on supply lines between Norway and Denmark in the Skagerrak sound, except for Norwegian ships transporting lumber bound for Britain. The resulting blockade isolated Norway from both Denmark and from the market and economically impacted Norway. Most exports were stopped, as well as grain imports from Denmark. The blockade resulted in an economic crisis for Denmark-Norway.