What do you thnk of a strategy where the UK leaves Norway alone and then the US takes it on US3? On its next move, the UK moves its AA gun to Norway, and then the US moves its eastern AA gun to the UK and puts an IC in Norway. Can the Allies hold the IC in Norway?

In a recent family game of A&A revised, we ended up in stalemate. All the players bought enormous amounts of infantry, which resulted in defensive positions so strong that no one could attack. We would like to change the rules so we do not have a stalemate in the next game. Do you have any suggestions?
One possibility would be to play to minor victory, 8 cities. (We usually play so 10 cities are a victory.) Problem is, I donâ€t see any way that the Allies could win that way.
Another suggestion would be to limit the amount of infantry a country can buy in one turn. Do any of you have experience playing with such rules?