The latest iteration of Force on Force is the Osprey book – published 2011.
Been a while since I played the old rules –
The significant difference in the rules is in the chain of reactions – The initiative (aggressor) unit resolves the reactions it succeeds in first rather than those it failed in first as in the original version.
There are no WW2 specific rules included.
The rules are more detailed & refined perhaps.
There is a large multinational vehicle detail section.
There are of course a number of ‘theatre’ supplements available, each have ‘locale’ rules.