Why did Remarque's novel cause so much controversy during the time period in which it was published?

All Quiet on the Western Front was published to great critical and commercial acclaim in 1929. It soon earned the wrath of the Nazi party for its anti-war and anti-nationalistic sentiments. Though burned and banned there, it has since sold over 50 million copies in dozens of languages, and is still considered by many the greatest anti-war novel of all time.