USA is one of the strongest nations in HOI4. Also because of its location, USA is really hard to invade. So, what is the best way to invade USA in HOI4? How to invade USA in HOI4?
The answer is complicated. Because it depends on the country you play. That is why I made two different guides for Japan and Germany. Since they are the two main enemies of USA, I believe these guides are highly useful. Especially for beginners.
HOI4 Invade USA As Japan
As Japan, you can easily invade USA islands in the pacific without facing much resistance. Your generals should have invader trait already by the time you get into a fight with USA. That will hugely reduce your invasion time. Once you have Hawaii, you can start the invading Los Angeles and San Diego ports. Then simply move all your troops to the ports you have secured with your invasion force. But before that, just make sure to have tons of convoys for transport and supply.
USA owns superior navy however half of their navy does gods knows what in the European seas.
Second invasion route would be the Attu Island > Alaska > Washington. This route can be abused pretty easily at 1936 by justifying early war goal.
Important: Don’t forget to split your destroyers and submarines from the main navy. That is the only way to increase your range for the naval invasion support.
HOI4 Invade USA As Germany
Easiest way would be taking out UK first. Start the war at 1939 as you would and destroy everyone in the Europe. Then, simply invade/paradrop Sussex to end the war. That was you can take UK lands in the North America with a peace deal. Labrador and Newfoundland to be specific.
After that build infrastructure in Newfoundland for supply. You can build airports too. Then it should be easy to take out USA as Germany thanks to the land connection in Canada.
Second way would be taking Colombia or Venezuela so that you can open a road to Mexico and eventually USA. By the way since Venezuela is also fascist, they may join the Axis and speed up this process. South American provinces have really low supply. So, building some transport planes for supply support is mandatory.
The main challenge is moving your armies to North America. Once you do that, you can easily win the land battles and conquer the USA.
Good luck, have fun and make sure to share your thoughts with me on invading USA in HOI4. Thank you.