When Russia first invaded Ukraine in late February many experts predicted that the vast Russian military would swiftly outnumber and defeat the defending forces.
However more than two weeks into the conflict Russia is still yet to have taken the capital city of Ukraine and the speed of the offensive seems to be slowing.
“The Russians have not achieved air superiority over the whole country,” a senior US defence official told reporters.
“Ukrainian air defences remain intact and viable both in terms of aircraft and missile defence systems, and they’re engaged.”
However President Putin presides over the second-largest air service of any nation in the world, behind only the United States.