从撇清关系到准备打击，美国会在以伊冲突中直接“下场”吗？

Group 1 - The article discusses the fluctuating stance of the U.S. President Trump regarding military action against Iran, indicating a shift from a non-interventionist approach to a more aggressive posture [1][3] - Following an Israeli airstrike on Iran, Trump expressed a desire for Iran to "unconditionally surrender" and hinted at potential U.S. military involvement [1][3] - The U.S. is reportedly increasing its military presence in the Middle East to bolster its defensive posture amid ongoing conflicts between Israel and Iran [3] Group 2 - Iran's leadership, particularly Supreme Leader Khamenei, has firmly rejected any notion of surrender and warned of severe consequences for U.S. military intervention [5] - Despite Trump's claims of Iran's willingness to negotiate, Iranian officials have denied any requests for talks with the U.S., asserting that they will not negotiate under pressure [5] - The ongoing conflict has led to a series of indirect negotiations between the U.S. and Iran regarding nuclear issues, which have been complicated by military actions [5]