I agree. Here are the principles of an empire:
1 - An empire is always singular.
2 - Chaos surrounds the empire, and only within it is there order.
3 - The empire has the moral right to bring its order to the chaos.
There have been many empires throughout history, and in China, for example, so many empires have risen and fallen... Moreover, half of them were nomadic (Tang, Yuan, Jin, etc.).
Today, the following can be identified as empires: the USA, China, South Korea, the EU, and partially Japan. Russia is a country with imperial ambitions, but without sufficient power to realize them.