Carl Schurz influences the Republican Party to adopt a "Pro-German" stance in foreign policy. Schurz is later appointed by a Republican president as foreign minister and works on building a relationship with the strong European power. When Schurz leaves office Republicans argue "if ain't broke, don't fix it" and continue his policies.
When WW1 breaks out Germany is blockaded and US protests, wanting to continue trade. Britain snubs them and tensions mount, eventually mounting into a conflict.