By Federico Maccioni DUBAI, April 28 (Reuters) - Iran warned last week that submarine cables in the Strait of Hormuz were a vulnerable point for the region's digital economy, raising concerns about potential attacks on critical infrastructure. The narrow waterway, already a chokepoint for global oil shipments, is equally vital for the digital world. Several fibre-optic cables snake across the seabed of the strait, connecting countries from India and Southeast Asia to Europe via the Gulf states and Egypt. WHAT MAKES UNDERSEA CABLES IMPORTANT?