JERUSALEM (Reuters) – The Ukrainian envoy to Israel voiced frustration on Monday with its refusal to provide what his country deems defensive aid against Russia, donning a helmet at a news conference and asking rhetorically how such equipment could be regarded as lethal. But Ambassador Yevgen Korniychuk also voiced gratitude for Israeli efforts to mediate between Russia and Ukraine, saying this outweighed any military assistance it might have provided. While condemning the Russian invasion of Ukraine, Israel has limited itself to humanitarian relief and kept open channels to Moscow. Israeli Pr…