Ahh, I came across that argument in an old Heinlein essay.

I've never come across anything which demonstrates that there's a real connection between the two. If that argument had any strong influence, I would have expected something different than what we got.

To start, the suburbanization movement started before the atomic bomb was development. The FHA started in the Depression, and it had a strong role in shaping suburbia.

Levittown - as representative of the post-war suburban boom - started before the Soviets had their first atomic bomb, back when we thought it would take them 10-20 years.

Nor did the US suburbanization movement change once we developed H-bombs, which are massively more destructive than atomic bombs. Nor did it change because of Soviet arms build-up, either the boogey-man "missile gap" which didn't exist, or the eventual buildup afterward to thousands of Soviet ICBMs.

For scale, the contiguous United States is 8M km² but most of it is unpopulated or rural. The US census at https://www.census.gov/geo/reference/ua/urban-rural-2010.htm... (column UAAREALAND from "Changes in urbanized areas from 2000 to 2010") says that 88K mile² of the US live in urban or urban clusters with at least 2,500 people. This includes suburbs. That's 226K km² across 500 distinct places.

The Soviets had 45,000 warheads, not all of which were on ICBMs. Each R-36M2 warhead has a yield of over 500KTons. Earlier models were in the megaton range. But lets say it was only 100 KTon like the W-76. The air blast radius for 100kTons is 33km². That's 7,000 nukes to destroy all non-hardened buildings in all urban and suburban location in the US.

The USSR clearly had the capability of destroying all urban and suburban regions of the US.

Furthermore, the suburbanization plan we put into place decentralized people, but not industry. (Heinlein pointed out the need to decentralize industry if we are to use decentralization as an effective counter to nuclear war, so this isn't a new observation.)

On top of that, zoning made the US less robust towards nuclear war. Once the oil refineries are destroyed, the car infrastructure will break down because the price of gas becomes exorbitant. If there were grocery stores, schools, and medical care centers in walking distance of most suburban areas (as promoted by the new urbanist movement) then those would help with the transition to a post-war car-less life.

For that matter, how would the suburbs in the NE US get its food once the transport hubs were destroyed? Why push people to the edges of the largest cities rather than really distribute them around the country?

IMO, if nuclear war survival were the real plan, a better strategy would have been to support small towns - really decentralize the country, and put people closer to where the food is grown. Instead, we got a mass migration to the cities (and suburbs), depopulating rural America.

Finally, the suburbanization plan was explicitly constructed to favor white people, not the best and brightest. If the expectation was that the Soviets would destroy the cities, but not the suburban populations who fled the urban core ("white flight"), then it would not only have been a racist policy, but a policy leaning towards of race genocide.

So, why do you think the US policy of subsidizing suburbia had any substantial connection to a defensive strategy against nuclear war?