Wilson’s speech to Congress, 2 Apr 1917 suggested 6 reasons:
1. Accused Ger. of abandoning “law & HUMANITY” by using U-boats to sink all ships near Allied ports incl. US ones → killed Am lives.
2. US ≠ seeking revenge but fighting to defend “human RIGHT”.
3. Ger. had filled US with SPIES; had tried to stir up trouble internally = ∴ could never be friend to US.
4. Zimmermann Telegram proved Ger. was plotting to get Mexico to attack US = threat on US border.
5. Prussian rule = anti-democratic → ∴ world must be made safe for DEMOCRACY
6. US fighting for: democracy, self-govt, small nations’ rights, peace & safety for all, a global system based on law & freedom = ‘a concert of FREE PEOPLES’.
7. Four other factors Wilson didn’t mention:
◦ Russian Tsar abdicated Mar 1917 → no longer awkward for US to ally w. Entente.
◦ Growing PREPAREDNESS MOVEMENT (from 1915): nationalistic, pro-war, wanted strong US (military & trade), believed trained soldiers = better workers.
◦ Economic boom:
– US trade doubled 1914–16.
– Gunpowder prod ↑ x60 – all exported.
– 1914 recession ended.
– Joining war = profit for arms firms (eg Bethlehem Steel, Remington Arms).