British RAF spy planes and submarine hunters circled above as US special forces boarded an empty Russian-flagged Venezuelan oil tanker in the north Atlantic in an expensive performance verging on satire. The Marinera was chased across the oceans, switched its nationality to Russian mid-journey, painted Moscow’s flag on its side and chugged along shadowed by one of Vladimir Putin’s submarines. But the elite sailors beneath the sea offered the ageing tanker no real protection. And while the