3) A bulwark of Alliances

Learn how to leverage alliances in Hearts of Iron IV to your advantage, from joining major powers to getting crucial support like expeditionary forces and blueprints.

Alright, let's talk about alliances in Hearts of Iron IV. Honestly, the diplomatic depth in this game is incredible, which is a huge plus! However, it can get a little unrealistic compared to real life, so take some of this advice with a grain of salt when you're thinking about actual history.

While there's a whole chapter dedicated to alliances themselves, it's super important to understand how they can seriously impact your wars right from the get-go. When you declare war on someone, all your allies immediately jump in too. Depending on where they are on the map, this can be a game-changer, either for the better or in a hilariously chaotic way.

You'll generally find three to four major alliances in the game. Most of the time, you'll either steer clear of forming your own or join one of these big players. Trust me, trying to form your own alliance is usually a costly and pretty pointless endeavor.

The big advantage of sticking with the major alliances is that you can often see who they're going to war with and when. You can use this foresight to pick an ally that'll get you into the least amount of trouble, and then really milk the alliance for all it's worth!

As the 'little brother' in a big alliance (another reason to go for the big guys and avoid making your own), you can expect some sweet benefits. You might get expeditionary forces sent your way (awesome!), use the alliance to snag blueprints for new technologies, get help with resource shortages, and best of all, your allies will often make a massive difference with their bombers and ships. More often than not, they'll be bombing your opponent's armies, hitting their industrial capacity, and their ships will be out there patrolling and blocking enemy trade, sometimes doing more than you even will!

But remember, it's a two-way street. You also get dragged into any wars that your alliance members get into. So, choose wisely!

When you're starting out in the game (around 1936-1939), it's usually easiest to join the Axis alliance, as they're gearing up for war and actively looking for partners. Later on, the Allies alliance becomes more accessible, though the Axis are still an option. Japan seems to be available pretty much throughout the game, as does the Comintern, though I find the latter can be a bit more restrictive.

Your nation's ideology and government, along with the general consensus of the alliance, plays a role in whether you'll be accepted. However, it's not always a deal-breaker. When an alliance is already at war, they tend to be much more willing to accept new members, so don't be afraid to try!