ALBAWABA- U.S. President Donald Trump has escalated his administration’s economic confrontation with China, threatening to impose punitive tariffs of up to 500% on nations purchasing Russian oil, a move that directly targets Beijing’s deepening energy ties with Moscow amid the ongoing Ukraine conflict. Speaking ahead of a possible meeting with Chinese President Xi Jinping at next month’s APEC summit, Trump warned that countries “doing business with Russia” would face “unprecedented ...