There are some rules for traveling through international waters that all the sailors must adhere to. If not taken seriously, the result would be the same as that shown in the video.
The video shows the Russian Navy destroying Somali pirates who entered international waters while manipulating the marine protocol. The Navy is authorized to take the action they took in the video in order to protect their side of the water, together with their ships and cargo, from any kind of destruction.
The waters are to be made safe for travel and trade, which is what the aim of the Navy remains. The brutal attack that was made on the Somali pirates was necessary for the Russians to protect their people from any kind of danger that might come their way.
The Navy looked confident during the attack as they had no fear of what they were doing. They were sure that they are right, whose thought seemed to motivate them even more when attacking the pirates. The step taken was both necessary and brave as this is what the Navy is for. The purpose they serve is beyond praise for which they are ready to give their lives.
The Somali pirates were definitely not prepared for the attack, which is why there was no sign of a counter attack in the video. They silently accepted their destruction while their ships burst into flames.