I'm doing a project where I have to write 1 word for the alphabet of WWI. I can NOT think of X! Can U help?

Xenophobia - fear of foreigners. It's a bit of a stretch, but no more so than x-rays (which everyone will have). One can argue that Xenophobia was responsible for the complex network treaties. Or that the U.K. and France didn't cooperate more because of Xenophobia.