Houthi missiles and drones are now hitting Saudi airports and killing civilians, a dangerous turn for the kingdom and a sign its expensive air defenses are failing.

• A Houthi ballistic missile hit a passenger terminal at Riyadh's main airport, killing 13 and wounding over 300 — the deadliest attack on Saudi civilians in a decade.
• The Houthis say the strikes are payback for Saudi air raids in Yemen, where they claim dozens of women and children have been killed since early September.
• Cheap drones and missiles are beating multi-million-dollar US-made interceptors, and Saudi Arabia has burned through most of its stockpile with replacements not due until 2028.
• Saudi forces are stretched thin flying strikes over Yemen while trying to guard a huge country with too many targets and too few defenses.
• The Houthis have openly said they want to topple Mohammed bin Salman, who is now moving between guarded palaces out of fear of assassination.

Outlook: Expect more strikes on Saudi cities, airports and oil sites, with the kingdom stuck between pulling back from Yemen or absorbing deeper damage at home.