This is binary: does nuclear Pakistan fall to Taliban or not? (the radicals in Pakistan are much crazier than the mullahs in Iran, and Pakistan already has a comprehensive nuclear weapons factory).
If not, then everything is a comparatively small problem on the real global scale if we take our dick out of the cuisinart.
Re benefits:
A stateman would reduce benefits to the boomers to keep the ratio of dependents to workers constant. It is of course political suicide, and the days of principled statesmen went out when Newt Gingrich arrived.
Most likely there will be a “deal” allying boomers with the usual capitalist oligarchs to allow large scale immigration of poor but young Mexicans to start paying payroll taxes to support the boomers. The standard of living of generation X (who will be in their prime earning years when the boomers retire and start screaming for more benefits) and Y will plunge with much higher taxes and worker competition. US citizen poor will be utterly screwed, like going back to Appalachia or the plantations.
Those two catastrophes are insignificant compared to the real enormous “nuclear war scale” biggies
1) 2010-on, peak oil, and in particular peak “net exports”. (Mexico may implode in 2 years due to its oil production available for hard-currency export in rapid decline)
People will temporarily survive because of massive exploitation of coal-to-liquids processing. Which leads to….
2) 2025++, runaway global warming.
Nuclear war might make a comeback if Pakistan goes tits up.
