One paragraph response summarizing the main causes and position of the U. S. under president Woodrow Wilson entering WWI.

USA had to join the war after altercations and provocations by the Germans.

Explanation:

America had remained neutral for almost all of the war until their trade ships began being sunk by  the Germans as USA was a major supplier of arms to the nations and then their trade routes were purposefully blocked.

There was also a plan revealed in the Zimmermann note about a conspiracy to get Mexico to declare war on the USA effectively starting a home front in the war for US.

This was what led US to get involved in the war directly.