Havana ? Fidel Castro took questions from Cuban ambassadors at the Foreign Ministry on Friday and warned them of the threat of global nuclear war in his most overtly political public act since re-emerging from four years of near total seclusion.

It was the revolutionary leader’s fifth appearance in less than a week, and the first in which he met with senior government officials. The sudden media blitz has many observers wondering if the 83-year-old former president plans to reinsert himself into Cuba’s political scene at a particularly sensitive time.

The government — now run by his brother Raul — is in the midst of freeing dozens of political prisoners, faces a severe economic malaise and has been cracking down on high-level corruption.