As Ukrainian troops try to stave off Russia's military from advancing through the eastern part of the country, they face tens of thousands of enemy soldiers. But when Ukraine's president sat in the Oval Office on Friday afternoon, he faced a different kind of battle — the blunt testiness of the U.S. Trump administration. The combative exchange left Ukraine's allies and many of its citizens in shock and dismay. Yet for others, there was pride in how Volodymyr Zelenskyy stood his ground. "I was angry, obviously," said Andriy Tkachuk, a Ukrainian soldier serving in the country's north who spoke to...