I believe there is something of a paradox here, in that societies achieve complexity in direct proportion to the amount of freedom that they enjoy, the stricter the boundaries set by government in which a society must operate, the less complex and less successful it is likely to be. My opinion.
However, if government must regulate certain aspects of a complex society, as it must, the more local the authority doing the regulating, the better.
"This has happened after every war"
Regarding WWII, this was probably exaggerated by the fact that FDR had strong ambitions of increasing and moving leftward the powers of central government.
"Thus, paradoxically the more rights we claim the larger the government must become to protect those rights."
No arguing that point, when people think, as they now do, of their "rights" as services or remunerations that government can provide for them, then government must grow.
Actually the complexity of a society increases merely from population growth without regard to freedom. Freedom does allow MORE complexity as well but it is not necessary for it to occur.
Actually I believe most of the growth in government has been on the local/state level in the last 30 or 40 yrs.
FDR had a very difficult problem to deal with even before the War and was a stop gap to prevent an even GREATER leftwad shift. During the thirties there was great concern that there would be a communist revolution here. He had attackers from the Left from within his own party such as Huey Long.
I realize it is very popular here to attack FDR but I think in all fairness one must look at the context of the times he was attempting to operate within. When 25-30% of the work force is unemployed and NO ONE can figure out why there is a huge problem.