If German or Soviet threat is high enough they will DOW without the event.
It doesn't sound like you have enough forces for an invasion, they would quickly be surrounded and eliminated if the Italians and Germans reacted to the invasion. Not really sure why you invaded Belgium though, even if they were aligning to the Axis, I've never heard of them joining the Axis before Germany invades them.
I've not played as Allies yet, but I think my strategy would be to combine forces. If the British launch an invasion, be prepared to back them up and ensure their beach head, rather than striking out alone. USA won't join Allies until they are attacked or they DOW on a high threat Germany or Soviet Union, so you can rule them out for awhile, regardless of their alignment, it will probably get to the December 1941 event before the threat is high enough for them DOW.
Still, my success rate is fairly low compared to most here
It doesn't sound like you have enough forces for an invasion, they would quickly be surrounded and eliminated if the Italians and Germans reacted to the invasion. Not really sure why you invaded Belgium though, even if they were aligning to the Axis, I've never heard of them joining the Axis before Germany invades them.
I've not played as Allies yet, but I think my strategy would be to combine forces. If the British launch an invasion, be prepared to back them up and ensure their beach head, rather than striking out alone. USA won't join Allies until they are attacked or they DOW on a high threat Germany or Soviet Union, so you can rule them out for awhile, regardless of their alignment, it will probably get to the December 1941 event before the threat is high enough for them DOW.
Still, my success rate is fairly low compared to most here