From the beginning, the Commonwealth of Independent States or CIS has been a weak and uncertain successor to the once-mighty Soviet Union. The ill-defined, loose federation has never been able to adequately pick up the pieces of the broken USSR, and the republics of the commonwealth increasingly have less in common with each other.

That reality was underscored last week when only seven of the 11 original members who established the CIS would sign a new charter that was supposed to help define and strengthen the alliance.Ukraine, Turkmenistan and Moldova refused to sign and Azerbaijan failed even to send delegates to the CIS summit. That left the CIS with only the independent republics of Russia, Belarus, Armenia, Kazakhstan, Kyrgyzstan, Tajikistan and Uzbekistan as charter backers. The vast Russian republic, of course, dominates the others in size, wealth and population.

Of the original 15 republics of the USSR, the three Baltic states reclaimed their original status as independent countries and the republic of Georgia never joined the CIS.

The idea of the CIS was a good one since many of the republics scarcely have the resources to prosper alone. But lingering jealousies, suspicions, ethnic conflicts and the fear of any new central government have kept the commonwealth from functioning very well.

Yet even the non-signers recognize that individual republics need each other. They need to share natural resources, transportation networks, communication links, military structures and many economic ties.

Most leaders of republics in the CIS agree on the economic interdependence. The problems arise on questions of armaments, collective security and other central government issues.

While many people have cheered the disintegration of the former Soviet Union, something like the CIS must be provided if the tens of millions of people who live in the various republics are to be protected against complete economic and political breakdown and anarchy.

It's probably impossible that the old Soviet Union can ever rise again. Humpty Dumpty has been broken into too many fragments. But the best hope for peaceful prosperity is a commonwealth that can learn to work together while still making allowances for serious differences.