Iran could expand its attacks if its foothold in Yemen comes under threat. Saudi Arabia must weigh a response against the risk of drawing in Iran, the U.S. and other allies and turning Yemen into a new regional flashpoint

Houthi strikes risk adding a new front to the Iran conflict.

Iran-backed Houthi rebels in Yemen launched a major attack on southwestern Saudi Arabia early Tuesday, targeting oil and other infrastructure in an escalation that risks widening…