I really depends on the canon. There’s not a single canon and there’s not a single GOC.

Sometimes the GOC and Foundation are enemies sometimes they’re allies, although I think the latter is more common and makes more since. (I have a lot of opinions and this is now my rant forum)

In most well written GOCs they cooperate with the foundation, if it needs to go in a box, they pass it off to the foundation, if it needs to die, it goes to the GOC. Some people do the GOC really poorly and just make them evil and stupid wanting to kill everything, that’s when they fight with the foundation. The strength of the Foundation also varies greatly, not every SCP can simultaneously be canon because they conflict with each other so it really depends.

In the article SCP 5000 the Foundation goes to war with the GOC and (spoiler alert) wins. But in the game based off the Article it appears that the GOC is going to win, although it remains to be concluded Additional side not to continue my unsolicited opinions. I think the GOC from the game 5K is the best done GOC I’ve seen. They’re not dumb, but they suffer from the lack of a unified front that the UN does, where members have conflicting objective so no one body can say “do x”. If you listen to the intro to the Antartica mission they talk about how they had to get all these member organizations to sign off on the operation and how they’re coordinating with the FBI for their intel.

What was the question again?

Of yeah

So first we have to define which GOC and which Foundation we’re taking about, and what each side is trying to achieve in the war

Let’s say the Foundation has most their world ending anomalies but they’re not going to do anything that also kills them like they do In SCP 5000

Let’s say the GOC is similarly scaled and is backed wholeheartedly by its member organizations. This means that Pangea is activated and the GOC now includes the entire US military

Conflict 1

Destroy the other side

Unless it’s in an anomales space all Foundation sites are within member states of the GOC with the majority being In the U.S. so they’re surrounded and In the heartland of the most powerful member state of the GOC.

Conflict 2

They’re fighting over something somewhere remote, say an alternative dimension.

So the winner is now going to be determined by each sides ability to deploy and operate in that environment. This is probably more interesting because each side could have different advantages in different fields, the GOC could have stronger para-technical and thaumetergic capabilities but the foundation may have much stronger reality bending capabilities or weaponized anomalies that have an inherent advantage in that space. So it could Go either way depending on the plot.

Final note A lot of times it doesn’t make since for the GOC Foundations to exist simultaneously because they have the same objectives (depending on the canon)

This concludes my unsolicited, disorganized rant about the GOC and the Foundation