As the world grapples with the spectre of escalation in West Asia, the last thing it needed is a reversion to chill cold war scenarios in Eurasia, of mutually assured destruction.

The sentence is in the present tense, as indicated by "As the world grapples." Therefore, "it needed" should be changed to "it needs" to match the tense. "Chill" should be corrected to "chilling" to convey the correct meaning and to be grammatically appropriate. "Chilling cold war scenarios" is the correct phrase here, meaning frightening or alarming cold war situations. "As the world grapples with the spectre of escalation in West Asia, the last thing it needs is a reversion to chilling cold war scenarios in Eurasia, of mutually assured destruction."