[AntEater]

If you look at past estimates, you will see a mixed bag
AFAIK the NIC failed to predict the collapse of the USSR.
On the other hand, while it did not predict 911 per se, it warned for years about major terrorist attacks on US soil.
It seems to me that while NIC is good on hard power politics, military, migration and industry, the US intelligence community knows little about the intricacies of the world financial markets.
This is not surprising as most intelligence services recruit themselves from the military or other security institutions.
Apart from that, as I posted in the "black swan theory" thread, the NIC apparently is quite good at recognizing trends.
And IMHO they're pretty much stating the obvious, and not giving a worst case scenario of that either, but rather an optimistic middle ground assessment.
With regards to america being more adaptable and such, intelligence agencies cannot count on metaphysics.
This sounds a bit like the WW2 japanese trusting that their japanese martial spirit might overcome any technological advantage of their enemies.

I mean if the US can integrate these non-traditional US citizens, it won't be because of some kind of special spirit, but because the economy can provide them with the same standard of living as the others.
With that I don't mean a welfare state, but well-paid jobs.
I'm not a US citizen, but to me it seems the great integrating factor in the past has not been some kind of economic kumbayah of a common spirit, but rather the fact that everybody who tried earned enough not only to keep living but to actually improve.