1. according to claudius, what was the ruin of athens?

Claudius felt the ruin of Athens was due to the fact they refused to grant citizenship to foreigners. In a way, this was probably true, in that by not allowing foreigners to enter they halted the growth of Athens, which meant the city became stagnant

The period of Detente was first begun by President Nixon.

Detente is a French term meaning "loosening" or "lightening". In many historical texts it is translated as "distension". The term is used mainly to refer to the reduction of tension between the Soviet Union and the United States in the melting process of the Cold War, which took place since the fall of the Nazi regime at the end of the decade of the 40 until the early 80's.

The most important treaties were not developed until the advent of the Nixon administration in 1969. The Warsaw Pact's political advisory committee invited the west to hold a summit on "security and cooperation in Europe". The West agreed, and negotiations began on the real limits of the nuclear capabilities of both superpowers. This ultimately led to the signing of the SALT I treaty. This treaty delimited the nuclear arsenals of each power, although it was quickly considered obsolete by the development of the MIRVs. That same year, the Biological Armaments Convention and the Anti-Ballistic Missile Treaty were signed. The negotiations on SALT II also began.