My current story is about just what I said in the title - a limited* nuclear engagement breaks out between the modern-day United States and Russian Federation. (*in this case, "limited" means ~120 strikes across the US - still pretty extensive, but not anywhere near a full-scale war) Obviously, this is the kind of thing that will not go unnoticed by the rest of the world, and the way they react to it will affect the course of the war, which will in turn have an effect on the plot of the story. I know some about foreign relations, but I'm not an expert by any means. In particular, I want to know about... NATO - obviously, Article 5 would be invoked immediately - "any attack against any NATO member state shall be considered an attack on NATO as a whole". But how might they react? Would Britain and France choose to go nuclear as well, and start lobbing missiles at Russia? Might they try something else first? Would they try to destroy the nukes that Russia has deployed in Crimea? Would NATO troops deploy anywhere, perhaps to bolster Ukraine? What if Russia decides to invade the Baltic states - Estonia, Latvia, & Lithuania, who are also NATO members? If things had not gone nuclear in Europe yet, might this push it over the threshold? Or might NATO decide not to go nuclear at all, at least not immediately? Ukraine - when the Ukrainians start to see American missiles light up the sky over the Russian horizon, could they be expected to take advantage of the situation and launch a swift blitzkrieg to take back Crimea, Donetsk, and Luhansk? China - Allies with Russia, but also has too large an economic reputation to uphold to risk much foreign intervention (hence why they've recently distanced themselves from N Korea). Would they support, condemn, remain neutral, try to play peacemaker? Hard to say how they'd react. I definitely want to hear from someone who might know a bit about China. North Korea - You know they love to try to make themselves relevant by forcing themselves into every matter. Hard to imagine they'd pass up the opportunity to attack American allies like South Korea and Japan. Is an invasion of South Korea likely? How about attacks against Japan and the Philippines? Is this the time when the DPRK might finally use whatever handful of nukes they have? Venezuela - a long-time adversary of the US, might they try to assert their influence in the Caribbean? A couple of Russian nukes have already cut off Puerto Rico from American support, so might Venezuela undertake an invasion of Puerto Rico, perhaps even the other US and British territories in the Lesser Antilles? If Venezuela did want to take Puerto Rico, would Russia help them? Or might Russia also want the island for themselves, and end up with the two fighting each other? American territories in the Pacific - this whole war started after a massive Russian naval wargame in the Pacific went wrong, so basically, the Russians are already all over the Pacific. Thus, I must wonder about America's many territories there - Guam, Marshall Islands, Wake Island, Johnston Atoll, etc. - would Russia make an effort to capture these, or would they just nuke them as they pass by? Japan - a major US ally and the closest to eastern Russia, but with little military capability of their own, what might they do? Give everything they've got to interfere with the Russian Navy? Or sit back and ride it out, hoping things don't turn against them?