Why undoing the 'tangled nest' of Iran sanctions won't be easy or quick for the US

The US has announced a 60-day reprieve from sanctions on Iran, allowing temporary oil and petrochemical trade, but dismantling decades of sanctions faces legal, political, and commercial challenges. The interim deal requires coordination with Congress, international bodies, and private-sector entities, with some sanctions tied to laws that only Congress can amend. Republican lawmakers have criticized the move.