How are Yemen's Houthis attacking Saudi Arabia so effectively?

Houthi rebels, who govern the northwestern region of Yemen, launched successful air strikes against Saudi Arabia's international airport and the headquarters of Saudi Aramco, the world's largest oil company, in recent weeks. These attacks have exposed the vulnerability of Saudi Arabia to threats from its neighboring country. The events have shattered the perception of Saudi Arabia as a secure and attractive investment hub, as the nation scrambles to attract foreign investment and diversify its economy beyond oil.

This alarming situation for a crucial US ally in the Gulf has been in the works for years, according to weapons and regional experts. They believe the Saudi Arabian vulnerability stems from a combination of factors, including Iran's support for the Houthis, which has enabled them to become proficient in producing and deploying advanced weaponry.

Iran has been providing the Houthis, formally known as Ansar Allah, with weapons, financial assistance, and military training for over a decade, although Tehran denies directly arming the group.