In regards to the question posed earlier, whether or not the Lubavitcher Rebbe OB"M opposed a new
Sanhedrin, he opposed an effort to establish a new
Sanhedrin in the early 1950's. His concern at the time was that such a
Sanhedrin would be a political rather than a strictly religious body, and would be used to promote a secular agenda, much like the "Sanhedrin" summoned by Napoleon in the early 1800's.
When I find the exact citation from Igros I will post it here.