Sentence:  The world has witnessed the first confrontation between the ‘<WSD>nukes</WSD>' and the ‘non-<WSD>nukes</WSD>' ["i.e.", countries possessing and not possessing nuclear weapons]. Although only a political one, this confrontation at the Review Conference of the Parties to the Non-Proliferation Treaty (NPT), which took place last May in Geneva, portends serious trouble ahead. 
Meaning of the word marked with <WSD> tags:  A nuclear weapon.