MANILA, Philippines — Vasily Lomachenko of Ukraine must be torn between pursuing a crucial bout against undisputed lightweight champion George Kambosos or joining his countrymen in a territorial defense against Russian forces. The 34-year-old Lomachenko, who won world titles as a featherweight, junior lightweight and lightweight, is scheduled to challenge Kambosos on June 5 in Australia. But the Russian invasion of Ukraine may force Lomachenko to take up arms. He was in Greece when the invasion began last week but has found his way home to be with his family, according to ESPN. The two-time Ol…