In my present game (Random-Zulus, Emp, Large 40% Archi), it's the early Modern era, and my very long cold war with Hannibal (mostly fought by Rome on my behalf) had just gone hot. My Cav-Armies (I only just got MotorTrans, and have only built a couple of Tanks so far) were in the last stages of taking apart his empire, but he's also somehow managed to annoy everyone else, and has lost a Tundra-town to the Ottomans (the most advanced + powerful Civ). The same turn as Ozzie also took Nora out from under my nose (using an impressively co-ordinated ship-bombardment followed by Marine-assault!), I captured Sabratha(?) and Carthage, finishing Hanni off — but that left a couple of small stacks of Ottoman Tanks + Sipahi running loose on my continent, which made me rather nervous. But I couldn't simply DoW Ozzie, because he has an MPP with the Vikings, currently the 2nd most powerful Civ on the board (I'm a close 3rd, because my military is smaller — but I have many more towns).
So I came up with a devilish plan: entice Ozzie into war (he was already Furious at me, and militarily stronger), and then get everyone else to fight him for me — primarily to sink his navy, because I've built very few ships myself.
I had been careful to keep my trade-rep intact throughout this game, so I temporarily zeroed my SCI%-slider (giving me >700 GPT income), and signed MPPs with Scandinavia, England (4th) and the USA (5th) — the latter two sharing their continent with Ozzie (and formerly Hammurabi). Then I asked Ozzie whether he wanted to share his monopoly on Fission (which he got as his freebie; he's already built both UN and Manhattan) or Computers (which I had already partly researched, with a SETI prebuild 8T from completion), but he wouldn't sell either of them, so I asked about AmphibWar instead: he was willing to sell that for my WMap and ~225 GPT. Then I told him to leave or declare, and — even though he had only a single Inf on my land at that point — he went ahead and DoW'd me!
I immediately destroyed all his Tanks + Sipahi I could reach in neutral territory, then ended the turn. During the IBT, I lost 1 of the 2 defending Infantries in one of my Carthaginian-captures to a combined Bomber + Sipahi attack; and 3 just-promoted elite Tanks (which were left damaged and in the open) to his remaining Tanks + Sipahi (1 defeated). His first bombing-run activated my MPPs, and since Lizzie already had an MPP with Hiawatha (who wouldn't bite when I offered, not even for >100 GPT), Ozzie was now at war with the Iroquois as well. Because everyone was now on my side, I was free to capture both the towns Ozzie held on my continent: in the meantime, he's fighting 5 of the 8 Civs remaining (he's not going to win any UN votes in the foreseeable future!), 4 of whom can easily get troops onto his lands, and I ended up paying nothing for AmphibWar (which I might still be able to use as trade-bait).
Even better, Lizzie finished researching Computers herself, reducing its cost, and War Happiness allowed me to lower LUX% and increase SCI%, so I now also have it, allowing me to switch my Palace-prebuild to SETI (now due in 5T), and start on Miniaturisation (for Internet). I also promptly sold Comps to Ragnar for >5000 gold (plus ~50 GPT, plus some other trifles), which let me instantly upgrade all my mainland Infs to MechInf (I have SunTzu). And best of all, my trade-rep is still intact.
And soon, PolandZululand will into Spaaaaaace!