> On the small scale, many indigenous tribal systems rely on a council during times of peace, and elect an executive (sometimes called a "war chief") during times of war.
That's how the Roman Republic operated, too: the Senate would elect a dictator for six months to handle certainly irregular situations. Unlike any other Roman official, he had no colleague who could countermand his orders, and he was not legally liable for any act he committed in office.
Nations almost all adopt an executive system because nations compete. The U.N. doesn't because Earth doesn't have to compete with anything else. Imagine a competitive interplanetary situation and you can bet the Secretary General of the U.N. would quickly gain significant decision making powers.
Collectivist market philosophies tend to be built on the assumption that there will be no competition internally and thus can be run by various committees. However, even countries trying to follow various types of collectivist ideologies ended up with single executive-types at the top, again because countries compete.
On the small scale, many indigenous tribal systems rely on a council during times of peace, and elect an executive (sometimes called a "war chief") during times of war.
The phrase "business is war" is particularly appropriate since most businesses operate like they're at war.