Houthi missile and drone attacks on Saudi Arabia's capital are escalating fast, bad news for the Saudi government and for oil markets, with crude already above $100.

• Riyadh's main international airport has been hit repeatedly, killing more than a dozen people and shutting the airport for the week.
• Saudi Arabia broke a years-long ceasefire with strikes in Yemen, including attacks that killed children, and the Houthis are hitting back hard.
• The Saudis are running out of interceptor missiles and are begging Pakistan and others for air defenses the US itself is short of.
• Cheap drones and maneuvering missiles let a poor country trade blows with a rich one, erasing the old gap between big and small militaries.
• Trump is offering intelligence help but little else, and reportedly has a side deal keeping the Houthis focused on Saudi shipping instead of American targets.
• Oil is above $100 a barrel, and tankers are also being struck in the Strait of Hormuz, pushing energy costs higher worldwide.

Outlook: Expect more strikes on Saudi soil and higher oil prices unless the Saudis stop escalating, with Israel pushing to join the fight.