Deep trenches, cheap drones, and a more efficient war machine are just some of the ways Russia has improved since it first invaded Ukraine

• Russia expected a swift victory against Ukraine when it first  invaded the country last February.
• A combination of strategic mistakes and strong Ukrainian resistance dashed those hopes.
• Russia has since improved its weapons and defense, setting the stage for a long, deadly war. 

When Russia first invaded Ukraine last February, Moscow shocked much of the West and the world when the country managed to fumble an apparent military advantage.