5. What are these other steps?

Iran is already talking about restarting construction of a heavy-water reactor that could produce plutonium, potentially opening another path to amass fissile material for a bomb. That decade-long project was disabled by the accord and would need significant work to reconstitute. The country could also break seals on thousands of mothballed centrifuges and begin introducing more advanced machines to enrich uranium faster. If it withdraws from the accord entirely, Iran could end the special access given to IAEA inspectors and curtail their powers to call surprise visits. In the worst case, it could even withdraw altogether from the nuclear Non-Proliferation Treaty, the multilateral 1968 accord meant to thwart the spread of nuclear arms. That’s what North Korea did three years before testing its first bomb.