There needs to be direct armed conflict, so stuff like cold war or proxy wars in general don't count.
US providing weapons to Ukraine (or any other country) but not operating them through its military also doesn't count.
In case of doubt, I'll ask random people within my social circle (not Russians, Americans and not Manifold users) whether the US is at war with Russia.
@mudPi314 only if they are clashing directly pretty clearly, but then I don't know if that would be considered a proxy war anymore. We'll also need some tolerance around "clashing", for example, I would not resolve US x Iran in January 2020 as war. Again, in case of doubt I'll just ask random people. If you have specific past conflicts that you would be unsure if they would resolve as Yes or No you can shoot them here and we will think how they would resolve if that helps
@GustavoMafra asking people could potentially be unreliable considering some Russians would currently say they're at war with the US / NATO already.