Drone boats give Ukraine a cheap, 'asymmetric' edge against Russia and may have just damaged a key bridge

• Waterborne drones are an inexpensive asset, giving Ukraine an "asymmetric" naval edge against Russia.
• Russia blamed Ukraine for using the drones to attack the Kerch Strait Bridge in Crimea on Monday.
• The bridge is key for Russian economic, military, and cultural interests in occupied Crimea. 

Ukraine has heavily relied on cheap-but-effective airborne drones for attacks on front-line Russian positions and on targets behind enemy lines. Waterborne drones are also inexpensive and devastating, and there are indications they were used to damage a key Russian bridge into Crimea.