By Mark Trevelyan LONDON (Reuters) – Russia’s leading war hawks on Wednesday swiftly rallied behind the decision to abandon the Ukrainian city of Kherson, putting a brave face on one of Moscow’s most humiliating retreats in nearly nine months of war. The pullout proposed by General Sergei Surovikin, appointed last month to take overall charge of Russia’s war effort, means Moscow is giving up a strategic city just north of annexed Crimea, the only Ukrainian provincial capital it had captured since its Feb. 24 invasion. With Ukraine threatening to pin Russian forces against the west bank of the …