3. Russia
Without a doubt, the Russian military is the second-strongest military force in the world. After the US and China, Russia has the second-biggest aircraft fleet, the largest submarine fleet, and the largest fleet of tanks in the world. They now have 766,055 frontline workers in action. The military budget of the Kremlin has grown by over a third since 2008 and is predicted to climb by 44% more during the following three years. By sending troops to Syria, Russia has also proven its capacity to project force internationally.