The hardest part realism-wise is how any would be invader would be able to gain an effective foothold to invade the US.
One thing I believe needs to have a bigger effect in the game is logistics. Taking this into consideration, invading the USA would require a staging point; a land border for a conventional invasion and a large naval base for an effective amphibious invasion. Mexico and Canada are the only neighboring countries on the continent, and I doubt the USA would sit idle as a foreign power either invaded one of these countries (Thanks, Monroe), or started transporting a large amount of it's military arsenal, munitions, personnel etc to it's borders. The most significant Naval bases I can think of on either side of the country are US bases (Guantanamo and Pearl Harbor). To take these you would already have to be at war with the US.
Either way, they have to contend with the USN before invading the country.
This leaves the only major power being able to effectively consider invading the USA the UK, and I don't believe they would have the capacity to achieve a decisive victory in the US mainland before the tide turns against them.
One thing I believe needs to have a bigger effect in the game is logistics. Taking this into consideration, invading the USA would require a staging point; a land border for a conventional invasion and a large naval base for an effective amphibious invasion. Mexico and Canada are the only neighboring countries on the continent, and I doubt the USA would sit idle as a foreign power either invaded one of these countries (Thanks, Monroe), or started transporting a large amount of it's military arsenal, munitions, personnel etc to it's borders. The most significant Naval bases I can think of on either side of the country are US bases (Guantanamo and Pearl Harbor). To take these you would already have to be at war with the US.
Either way, they have to contend with the USN before invading the country.
This leaves the only major power being able to effectively consider invading the USA the UK, and I don't believe they would have the capacity to achieve a decisive victory in the US mainland before the tide turns against them.
- 1