Given the world was at war, how were the central powers defeated?

There were many factors that contributed to the defeat of the Central Powers during WWI.:

1- Failure of the Schlieffen Plan: this made Germans fight in two fronts.

2- Naval powers: the naval powers of the Allied were superior to those of the Central Powers.

3- Failure of the Submarine Campaign: that brought the USA into the war.

4- Political leaders: the political leaders of the Allied were much more competent than the leaders of the Central Powers.

5- German great losses.

One of reasons the Central Powers were defeated was the entrance of the US forces into the war brought vast new resources to the allied forces. This also meant that the Allied forces were able to produce more war materials than the Central Powers, which proved to be decisive.

they wanted the u.s. to fight on the side of the central powers.