Should countries pursue policies of imperialism, or empire expansion?

I think countries should pursue policies of imperialism rather than empire expansion. An empire can expand as much as it wants. The issue is How they do it. With policies of imperialism, it can be inferred that ones country will be limited to specific details on how they can take a part of another country. The key here is having an equal advantage that benefits all of the world.

Take imperialism in China for example. The Spheres of Influence. Every country involved was somehow limited to something. Whether it be not being able to interfere with another country's trade or not being able to make one sphere more powerful than the others. Every one had an equal chance to have more power in some type of way.

If a country were to pursue policies of empire expansion, how would anyone cooperate? A country some how in some way needs to expand its empire. Have you thought about their motives? What if they are in need of certain resources for their country?