Game plot... not understandable.

[DrunkenQueen]

Why Russia suddenly attack Europe for?
I firstly thought that they sent a large army attacking the East Coast of the USA, and then they could send reinforcements quickly by attacking the West Coast.
I just find it weird that Russia attacked Europe as this would bring more enemies into a fight, which is likely repeating what Nazi Germany and Imperial Japan did in WW2.

It doesnt look like World War 3 to me. It's simply just Americans and Russians fighting in major, while the battle sets in Europe. I didnt even see German, French and British army. Only some special forces. And NATO seems not exist in that game universe.

(Seems Europe is a popular spot for World wars.)

[Laptop]

You never played MW2? Makarov did an airport shootout but framed it so it looked like the CIA did it (so the USA were framed to make it look like they did it).

Russia thinks the USA has done it, so they invade the USA and start a war.

In MW3, Makarov detonates chemical bombs all across miltiary / intelligence bases all through Europe, which allows Russia to invade Europe. Europe is considered more friendly towards the US than Russia, so that's why they were attacked. This prompts America who have just kicked our Russia from the US, to go over to Europe to help them out against Russia.

And there are plenty of British, French and German soldiers in the later levels...