"Of course Taiwan probebly already has the bomb. "
I'm very glad you pointed that out. Even having just 2 nuclear missiles changes the balance of power in that region.
That brings up all kinds of contingencies. What if they actually use the 2 devices? It would be the end of Taiwan. They send 2 nukes to Shanghai and Beijing and China retaliates by flattening the entire island. Tens of Millions of casualties on both sides. Taiwan "loses".
What if they don't use them? China invades, suffers millions of casualties in a war of attrition, finally wins. Taiwan loses.
This does put more leverage into my original post which stated that the Chinese army would probably do a run through VietNam first. Then Taiwan would be forced to hit VietNam with nukes in order to knock out the offensive capability of China's Army/Navy.
I think in the overall strategic view, Taiwan would need at least a dozen nuclear warheads to really tilt the balance of power. But they would still be annihilated in the end.
China threatens but never mobilizes its military or builds its forces up to actually attack. A combination of the possibility of Taiwan beig nuclear armed (in addition to their own well-trained and equipped conventional forces) and being protected by the US is what deters China from actually attacking. Taiwan should and probebly already does have a MAD policy.