How does that suggest that de-nuclearisation is easier than previously believed? The conventional wisdom (according to Carpenter, but I would disagree) was that Britain and France's priority was not to lose nuclear supremacy in the EU, so while they would rather have disarmed they did not want to be the first to do so. The new cables imply that at least France independently wants to have a deterrent, and as a consequence also pushes for Britain to maintain theirs: this is a scenario where disarmament is significantly harder, not easier.

Furthermore, Yglesias' point that the UK and France being nuclear powers incites "tier 2" economic powers to acquire nukes as a status symbol seems reasonable to me. However, if our priority is avoiding a nuclear war, then Brazil and South Africa stockpiling nukes for status purposes is a much more remote concern than Asian countries stockpiling nukes so they can engage in mini-Cold Wars over Kashmir, Taiwan, or the 38th parallel. And for the latter group of countries, the overwhelming reason for nuclearisation is to counter or surpass their direct opponents' nuclear arsenals; British and French armaments don't really enter much into the picture.

In some states. What genuine need do Britain & France have for nukes? The EU is a pretty safe neighborhood. If they were stuck next to China and India and North Korea and Iran, it'd be vastly more impressive.

Also: go Wikileaks.