• US President Donald Trump has sent Congress formal notification of resumed hostilities against Iran.
• The notification opens a new 60-day window for military action without congressional approval.
• The US began attacking Iran on February 28, alongside Israel.
• Trump claims the action is consistent with his responsibility to protect Americans and US national security.

This development may indicate an escalation of the US-Iran conflict, which could have significant implications for regional security and global energy markets. The move suggests that the Trump administration is willing to take a more aggressive stance against Iran, which could lead to further tensions and potential military engagements.