You are describing a co-op, not a government. Governments are distinguished by the fact that they employ force against non-aggressors, people who didn't choose to join. Give up that claim to "legitimate" aggression and I promise we will have no further objection to any kind of mutual defense or common-interest work you may choose to pursue with other like-minded, voluntary participants.
P.S. Those third-world countries you mention have governments, typically ones which are corrupt, highly authoritarian, and often based on unworkable and unjust principles; that's generally the main source of their poverty. (That includes places like Somalia; their government is highly decentralized, distributed among their tribal elders, but it definitely exists. The unstable proto-governments set up by Western nations from time to time also contribute to the problem.) Little or no government can work out just fine, but intrusive and disruptive governments are killers.