H. RES. 139 calls on the United Kingdom, France, and Germany to trigger the "snapback" mechanism under United Nations Security Council Resolution 2231, which would reinstate international sanctions on Iran due to its non-compliance with the Joint Comprehensive Plan of Action...
Simple Explanation
The bill wants some European countries to help bring back strong penalties on Iran because Iran didn't follow important rules about its nuclear program. It says Iran hasn't been playing fair, and the bill asks for action before a certain deadline.