I like this thread idea, RRW. Let's go, shall we?
China vs Japan & South Korea
China, hands-down. Even if the Japanese got rid of the constitutional thing and instituted a draft, the aging population would be killer. While they and the Koreans probably have the technological edge, sadly the full-scale Gundam probably couldn't be built in three months, meaning that Japan would be hoed, unless, like Israel, they have nuclear weapons they haven't revealed. We'd probably see some cession of South Korean territory to North Korea in exchange for no-nuclear promises and the threat of the nuclear devastation that wrecked Japan.
Indonesia has raw numbers, like the Chinese, and mild naval capability. Australia has the tech. Their borders are close enough that they could launch land-borne air attacks against each other; Australia would probably gain air superiority, but couldn't match that with significant land gains. It would be like a modern war against a backwards Shaka: he throws six 100-unit stacks your way which you kill at heavy losses.
What?

Okay, um....South Korea. Haxxor war takes place, with all Korean MMOs re-released in WAR VERSION to hack into Japanese databases and stuff. Japan eventually DOES build Gundam, but Korea retaliates with uber-Roan (Ragnarok ref; sadly, it's part Japanese, part Korean) and they reach a stalemate. Then, out of nowhere, Korean nukes rape Japan. While the whole world was focusing on North Korea, nobody realized the cute little brother the older, mentally deranged one whose writings in blood were about was really the one doing nuclear tests.
Iran vs Turkey (juicy one)
...zum...Turkey?

No idea. Um......Iran tries to invade through....Iraq? Azerbaijan/Armenia? And then Turkey does....something? No clue here.
BURNING SANDS [euphemism for female dogs]!!! :burn:
Israel takes Sinai, nukes the Great Pyramid, nukes Cairo, then eats Palestinian babies for dinner.
I jest, I jest.
(only about the babies part, tho)
Russia vs Turkey, Ukraine and Georgia
The Estranged Alliance beats Big Brother.
Another WTH option. Um....The Poles sense an opportunity to further redefine the center line of Europe and push the Ukranians to Crimea, then annex them to Russia, then claim that such actions resulted in Ulaanbataar becoming the new Warsaw in terms of East-West divide, forcing the EU to recognize them in a resolution passed by the European Parliament as Western European.
Either way, still a GOOOOOOOOOOOOOOOOOOOOOOOOAAAAAAAAAAAAAAAALLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLL!
Columbia vs Venezuela and Ecuador
The latter alliance, but then DEMOCRACY KICKS IN and everyone is happy.