Why is Israel
selling arms to China? And why does Israel need nuclear missile-equipped submarines ?

Israel must have the ability to defend itself regionally. It's obvious Israel has nukes, though they have never admitted it. It's simply deterrence. However, nuclear submarines are not regional-defensive, they are globally-offensive. If Israel had military enemies on a global scale or was facing an arms race against a foe on the other side of the world, then subs make sense.

How far do Sharon's ambitions go?