BEIJING A blunt but nonconfrontational exchange this week between the United States and China suggested that a strategic dialogue that began between the two countries last month may succeed in easing tensions in a relationship that is frequently troubled. The strategic dialogue is intended to resolve longstanding differences between Beijing and Washington over human rights, Taiwan, trade and weapons control. The exchange between senior officials this week also included a reference to the two countries’ opposing positions on the issue of Iran’s nuclear program. Full Story