The truce between the US and Iran has collapsed, oil is climbing back toward $100, and both sides are now hitting civilian targets — bad for the region and for the global economy.

• Four American soldiers were killed in Iranian attacks on bases in Jordan and Iraq, triggering heavy US retaliation strikes.
• The fight is really about the Strait of Hormuz, the waterway carrying a quarter of the world's oil; Iran keeps disrupting it, and ships are afraid to move.
• Iran used the short peace deal to rush out 70 million barrels of oil for cash and to relieve pressure on its oil wells, so it can now outlast a long fight.
• Both sides are bombing civilian infrastructure — hospitals, water plants, power stations — in Iran, Kuwait, and other Gulf states that rely heavily on desalination for drinking water.
• The US says it is preparing for a wider war but is running low on air-defense and long-range missiles, while Iran has gotten better at dodging US defenses.

Outlook: With Iran rejecting Qatar's ceasefire offer and both sides rearming, a return to full-scale war looks more likely than peace, which would push oil prices sharply higher.