Geopoliticalmonitor.com has followed the progress of the Shiite Houthi rebels very closely as they descended from the mountains in the north; sacked Sana’a and deposed the government of President Hadi; captured critical oil fields to the east of the capital; and marched southward towards Aden, the former capital of South Yemen where Hadi had taken refuge in the hope of mounting a counterattack.

Throughout the course of these events, it was an open question how Saudi Arabia would respond. Yemen, after all, with its near 50-50 split between Sunnis and Shiites and proximity to the Kingdom, represents fertile ground in the battle between Saudi Arabia and Iran – a rivalry that is increasingly unfettered as Washington experiments with a more balanced engagement in the region.

Well it seems we have our answer.