Explainer-What are Iran's options to escalate further in face of US economic threats?

U.S. threats of "the toughest sanctions" risk further escalation with Iran and its allies in the Gulf.
Iran and Houthi attacks have already disrupted shipping—threats to close the Strait of Hormuz or block the Red Sea could push up global oil prices.
Tehran could retaliate indirectly—striking Gulf targets, critical infrastructure (power/desalination) or using cyberattacks and covert operations abroad.