How did forming alliances increase the likelihood of war?

Forming alliances can increase the likelihood of war by creating a network of obligations and expectations among nations, which can lead to entanglements in conflicts. When one nation is attacked, its allies may feel compelled to respond militarily, escalating a localized conflict into a broader war. Additionally, alliances can foster an environment of mistrust and competition, as countries may feel threatened by the collective strength of opposing alliances. Thus, rather than deterring war, alliances can inadvertently encourage and magnify conflicts.