
The Kree, obtained from http://marvel.com/universe/Kree
In Annihilation, the Kree were the primary adversary of Annihilus and his alien invaders. The massive armies of the Kree held Annihilus' forces at bay until Nova, the Silver Surfer, and Galactus were able to defeat them. This conflict left much of the worlds controlled by the Kree devastated.

Annihilus, obtained from http://marvel.com/universe/Annihilus
Then in Annihilation: Conquest, the Kree tried to resist the Phalanx with military force but were eventually overwhelmed. Even though the battle with the Phalanx ended, the Kree people were ravaged and much of the Kree empire was devastated.
The Kree then joined forces with the Inhumans in order to restore some of their strength. But only days after this union, the Kree went to war with the Shiar. Now, the Kree are part of a multi-race coalition of forces battling invaders from another dimension.
It's hard to imagine the war force that could sustain this level of conflict for so long. But the Kree are that force. In fact, though it seems like they have recently been thrown through a wringer of conflict, the Kree have always been at war. For hundreds of years, the Kree have battled the Skrulls.
They clearly know how to run a war. The level of production and construction shown in the Kree is truly something impressive. Looking at the Kree in a Keynesian perspective would lend us to believe that the state of a permanent wartime economy would increase spending, up product demand, dramatically advance technology, and raise productivity. And the Kree certainly seem strong.
Of course, this has also led the Kree to become a completely militaristic society. They would be unable to function under any other system since their economy is centered entirely around war.
And it's hard to tell whether this is a bad thing. On one hand, the Kree kill a lot and die a lot. On the other hand, the Kree were responsible for holding off forces which could have destroyed the universe. The Kree are unique in their ability to destroy, but their economic and military strength is truly something wonderful to behold.