Why was the United States so reluctant to enter World War I?

The United States did not feel immediately threatened in 1914 when the war began.  The government did perceive some threats, but it was mainly from the anarchist and labor movements.  The United States hoped to trade with both the Entente and the Central Powers, though it soon switched to mainly trading with the Entente Powers because the Central Powers did not have the navy to get past the British blockade.  The United States thought that...

The United States did not feel immediately threatened in 1914 when the war began.  The government did perceive some threats, but it was mainly from the anarchist and labor movements.  The United States hoped to trade with both the Entente and the Central Powers, though it soon switched to mainly trading with the Entente Powers because the Central Powers did not have the navy to get past the British blockade.  The United States thought that it could count on being surrounded by two oceans to protect itself from a European struggle.  The progressive activists in the country feared that war would get in the way of their domestic agenda.  

Even when war came to the United States in the form of submarine attacks on American citizens and goods, the United States refused to get into the war.  Woodrow Wilson claimed that the United States was "too proud to fight."  There was a concern that the United States military was not prepared to fight the huge armies of the Central Powers, as the army's last meaningful experience was in the Spanish-American War.  The people of the United States saw the war as a squabble among European powers over territory that did not concern the United States.  The United States only went to war after the discovery of the Zimmerman telegram, which promised Mexico the American West, and the continuation of German unrestricted submarine warfare, which sank many American ships.  Even when the United States joined the war, it did not join as an ally of Britain and France. Instead, the United States was described as an "associated" power.  This was done so the United States could still claim the moral high ground when the conflict ended.