WW1 had numerous participating countries within Europe and elsewhere. It was a brutal, and many say totally senseless, war (as they usually are). The waste of life, goods, property, etc. was truly disgusting (as it always is). That was 100 years ago.
In the UK there has now passed a year throughout which a long series of media items, public commemorations, etc. have picked up the "100 years ago...." theme of recounting all manner of events involving various people - all of them WW1 related. It seems we are in for a further three years of much the same. I know of nowhere else in the "Western World" where so single-mindedly and relentlessly details of a century-ago-war have been constantly kept in the public eye.
At one point the Prime Minister stated that the victory at Agincourt 600 years ago should be the subject of public celebration - and he wasn't joking.
The UK seems obsessed with past battles and wars. I find this a truly depressing tendency/characteristic. And don't let anyone bring out the "We must learn the lessons..." argument to justify this unimaginative grind.