What would of happened if Pearl Harbour never took place?

US would have a more powerful fleet with battleships assisting the aircraft carriers.

The Japanese had invaded the Philippines which was US territory. We would have went to war over that.

It is likely that the USA would never have entered the war and the USSR would have defeated Germany on its own. This would have led to Communist dominated Europe and possibly have led to the Russians creating the first atomic bomb due to the fact that they would have captured all the German atomic and rocket scientist that in World War 2 went to the USA and GB. This in turn may have led to Russian global hegemony and the creation of a communist society throughout most of the world.

It is either that or USA joins war anyway and WW2 follows a similar course as before.

The USA would have never exploded the atomic bomb on top of Hiroshima.. so yes strictly speaking the Japanese fcked it all up.

Your IF is the key to your question. For this event was engineered by the US. In order to overcome the pro- German support by big business and majority of politicians.