The main reason why America joined WWI was the German's use of submarines in the North Atlantic and the Mediterranean.
<h3>What were British strategies in WWI?</h3>
The main strategy of the British during World War I was the use of blockade of Germany so that they would be cut off from supplies.
Hence, we can see that the British and German navies were locked in battle and this made it difficult for America to remain neutral in the war the United States decided to join the war after the blockade which led to economic difficulty for America also the presence of German U-boats.
