Based on the discussion in the "controversial opinions" thread, it seems it is time again for our annual thread on the Earth Romulan war
Now of course with updated information from DIS, PIC & SNW.
It's all my personal headcanon, but for me the Romulan War goes something like this:

Now of course with updated information from DIS, PIC & SNW.
I’ve always wondered if there’s any significance to the fact it’s called the “Earth-Romulan War.”
In the real world, it’s an artifact that “Balance of Terror” was produced for TOS before the Federation or Starfleet had even been given names and created as concepts for the show.
But in-universe, I wonder that since the name is not “Coalition-Romulan War” that it signifies the Romulans were able to divide the Coalition we see in Enterprise (maybe at least in the beginning), and Earth may have stood alone initially? It’s interesting that Enterprise shows a lot of delegates for the coalition, but only the Vulcans, Tellarites and Andorians join with us to become the founders of the Federation.
Sisko has a line in DS9 that’s always intrigued me. He warns the Federation president that if the Dominion are able to land Jem’Hadar troops on Earth, the planet will see the sort of conflict it hasn’t experienced “since the founding of the Federation.” I’ve always wondered if that implies the Romulans were able to attack Earth in some sort of massive way during the war. And the reason it’s called the Earth-Romulan War is that we took the brunt of the fighting.
That's always pretty much what I figured; Archer's "we'll go it alone" speech almost writes itself.
I've never thought about that fully, but it makes sense. Reman shock troops trying to land on Earth perhaps? There are similar lines regarding the Breen attack and Earth having not seen a direct attack like that for some time, though I cannot remember the specific line. Martok does note that not even the Klingons dared attack Earth directly, which is interesting juxtaposed with your idea.
Controversial Opinion/Personal Headcanon: The Battle of Cheron (which in canon is supposed to be the pivotal battle of the Earth-Romulan War) and occurs in some fictional star system (that may be the home to the half-white, half-black people from "Let That Be Your Last Battlefield"), should be retconned to be the "Battle of Charon" and occur around Pluto's moon, Charon.
I think that makes more sense given the fact that in TNG's "The Defector" it's referred to as a "humiliating" defeat that still bothers the Romulans two centuries later. Think about a huge Romulan fleet on the edge of our solar system, having already got some of their ships through in attacking Earth, poised to achieve a stunning victory against humanity, only to be turned back in the end at a pivotal battle near Pluto.
It's all my personal headcanon, but for me the Romulan War goes something like this:
- Romulans see Earth is successfully building a coalition, and attacks before the defense alliance is formalized
- The Romulans use drone ships, the fighting takes place almost exclusively in Earth space, kind of a reverse Afghanistan, the Romulans spread terror, but even when shot down their drones self destruct, so the humans learn very little, not even what Romulans look like
- Earth's allies don't want to get involved directly - war is unpopular - but they support with a lot of resources. Once they realise humans actually stand a chance, they even hand over their superior technology
- Earth manages to fastly build up a large fleet - NX ships, build with Andorian steel and weapons, Vulcan sensors and engines, Tellarite shields, and human crews
- Earth gets a critical win - it manages to bring the war into Romulan space (battle of Charon).
- The Romulan public and senate changes their mind - they don't want dead Romulans, they don't want war on their home turf.
- The Romulans sign a peace treaty with the humans. Weaponized drone ships become outlawed (that's why we never see them in TOS or TNG) A neutral zone gets established
- Earth suddenly has the biggest & most technologically advanced standing fleet of the allies. The Federation is formally founded. Starfleet with it's human-designed ship becomes the de-facto main military power (like America is in NATO), but politically & socially all members are equal. Archer holds a speech. He mentions a gazelle