According to Landor, it's based on a 1920s typeface (unnamed) that they then modified:

http://landor.com/#!/work/case-studies/council-on-foreign-relations/

Futura (designed in 1927) comes very close, save for the angle of the stroke terminals on the C.

There is a companion CRF monogram that appears to be based on Bernhard Script and/or Baskerville.

Dutch Type Library's version of Nobel looks close. I would say the Font Bureau version but the N is different. Nobel was released in 1929, just two years after Futura.

Nobel works for me, Rob, when it comes to the crossbar of the G and other details.

They appear to have rounded the C, O and G to be closer to perfectly circular--more like those same letters in Futura. Landor did say it was customized....

Thank you, gentlemen. Considering it could be based on Nobel, then it seems they also modified the "N", which looks close to Futura.

What is your opinion on modifying a font this way, with elements that are clearly typical from another font? Personally, I do like the overall result. But for a true typophile, wouldn't this approach lack consistency?

I agree that the overall result is quite pleasing. As long as it holds together visually, I don't mind the Dr. Frankenstein approach--provided the stitches and bolts aren't visible.

Too many times I've tried to help someone ID a logo typeface on this forum, and they've expressed disappointment that it wasn't a readily available typeface without alterations. Landor always does very subtle work (some may call it boring), but making the complex look simple and effortless is a real talent.

Better than the alternative: http://cuttingedgelogos.tumblr.com/