Houthi forces took control of Yemen's Red Sea coast in days, a bad turn for Saudi Arabia, oil shippers, and anyone buying gas or groceries.

• Houthi fighters swept south and grabbed thousands of square kilometers plus the islands guarding Bab al-Mandab, the narrow gate into the Red Sea.
• Saudi-backed Yemeni units collapsed fast, partly because many battalions were padded with fake troops who existed only on payroll.
• Saudi Arabia's main oil pipeline to the Red Sea is down, and even once it restarts, exports have to take the long route around Africa.
• Oil was already near $110 a barrel before this, and Europe is now warning inflation will stick around longer than hoped.
• Saudi and US forces are stretched thin from fighting Iran, and air strikes alone cannot push out fighters defending their own homes.

Outlook: Oil prices are likely to jump when markets open, with no sign either Iran or the Houthis plan to stop soon.