2) Germany and Italy
Germany and Italy were the first nations to ally with the common purpose of destabilizing the European order, it happened at the end of the year of 1936. Days later, Japan joined Germany by signing a pact of alliance directed at the Soviet Union, called the Anti-Comintern Pact. A year later, Italy joined the pact.
Eventually, these three countries formalized their alliance to fight in WWII in September 1940 when they signed the Tripartite Pact, which became known as the Axis alliance.
Along the war, other countries also joined on the side of the Axis, namely, Romania, Bulgaria, Finland, Hungary, Slovakia, and Croatia.
