WITH EQUAL MEASURES of incompetence and greed, the government of the District of Columbia has managed for years to delay, obstruct and otherwise deny to its citizens the marvels of cable television. Some local politicians have simply ignored the potential of cable, apparently because its complexities make their heads hurt. Others have scared away prospective operators by demanding gold-plated systems, apparently thinking that every social problem the city has ever had can be addressed by changes in the way television is distributed.

So while 30 million American homes now can tune to Ted Turner news, the Playboy Channel, and dozens of other cable choices, residents of the District have been left behind, fiddling with rabbit ears and cursing the snow. This year, as cable rights are awarded to the very last remaining tiny handful of unwired big American cities, Mayor Marion Barry has appointed a blue-ribbon commission to study the issue. And without guessing how effective the commission will be in getting the show on the road, let it be noted that the panel is replete with representatives ranging from the the lesbian-rights activist to the former Carter administration communications adviser.

Well, hooray for Washington. We may have done something right, for once. In a happy consequence of sluggish behavior, the D.C. government now has an opportunity to put Washington ahead of every other city in the United States. All it will take is the courage, for two or three more years, to continue to do nothing. Absolutely nothing.

Notwithstanding all the gee-whiz propaganda of the operators, the cable television systems being built in the U.S. today use a technology of copper-cable wiring that's obsolete. It has more in common with the hand- cranked telephone than with the futuristic communications systems that will define the society and economy of tomorrow.

It's easy to understand why cable companies have used such antique techniques: Cities have required them to. In the race to win franchise rights, cable operators have been forced to promise rapid construction. They have thus been prevented from making use of a far more promising technology -- called fiber-optics -- that will be ready for widespread use in two or three years.

Fiber optics are to copper wires as the space shuttle is to the Wright Flyer. At best, the most advanced copper cable systems still only brings you the likes of missable Home Box Office grade-B movies, 24-hour weather of primary interest to the Russian air force, and continuous tin-cup rattling by video evangelists.

The channel capacity, by contrast, of fiber optics is measured in the thousands. For Washington to have the economic advantage in the an information-based economy, for the city to retain its enviable position as information capital of planet Earth, and for profound reasons of national security, it is necessary for Washington not to straggle in at the tail-end of copper-cable technology, but wait for fiber optics.

While copper cable systems are, for the most part, simply another broadcast medium, fiber optics are capable of providing entirely new types of individually tailored services, including the possibility of "dial-up" video in which subscribers could select any program, at any time, without reference to program schedules, as well as futuristic communications systems.

Fiber optics involve laser transmissions along hair-thin waveguides made of transparent glass fibers. Its system offers the architectural sophistication, transmission capacity, switchability, reliability and privacy necessary for the data, voice and image communications systems that will define the society of tomorrow.

Because the capacity of fiber optics is so immense, there will be no need to establish elaborate regulations to determine who will have access to channels: There can be enough capacity for everyone. Instead of having to run a second wire into the home to provide cable TV services, fiber optics offer the chance to simply replace the existing telephone link, creating a single, economical information pipeline into every home and office. And because fiber optics can be readily integrated into the existing telephone system, they will eventually be far cheaper than any copper-cable alternative, because fiber optics produce more communications at a lower unit price.

Advanced communications services are not just another element in this game. They are the game. Whether it's the president being able to punch a button and have instantaneous desk-to-desk videoconferences with his cabinet, the linking of networks of personal computers, electronic mail, banking and shopping, or "dialing up" a particular episode of Family Feud, fiber optics can deliver the broad spectrum of current and future communications services.

Scientists at Bell Labs already know how to "download" digital movies, in high-speed bursts of data, into memory units on TV sets. The Japanese are already building fiber-optic systems in cities. The French plan national deployment of optic systems within this decade. MCI, the long-distance telecommunications company, has just placed a $50- to $100 million order for 62,000 miles of fiber optics. The Defense Department is being given fits by the prospect of Electro-Magnetic Pulse (EMP) damage to national communications in the event of nuclear war; fiber-optics systems are virtually immune to EMP and highly resistant to hostile wiretaps. Its time for Washington to get a truly capable fiber optics network.

This, however, will require a willingness to make new kinds of political, economic and financial arrangements. Although the idea might seem unfashionable, the best way to get such a network constructed would be to give theejob to the telephone company -- in this case the AT&T-divested C&P Telephone Co. The system could then be properly integrated into the existing communications system and regulated as a common carrier, with access available to all on a non-discriminatory basis. Although this approach may produce less pork on which District politicians could feast, there seems little doubt that the public would be well served by such a regulatory and operational structure.

It's not really a hardship if Washington decides to wait a little longer for cable. Even if the D.C. government gave the green light to an operator tomorrow, which it won't, most of Washington wouldn't see cable service until around 1986. Based on European, Japanese and experimental U.S. work, construction of a national capital optic system could commence within two years.

It would assuredly be a special disaster for the District of Columbia to ignore the necessity for planning a versatile communications system designed with the needs of the future in mind. This city, more than any other in the United States, and probably in the world, has an economy based on information. To stay on the cutting edge, the nation's capital must have communications second to none. Washington is missing little without cable TV. If the city can have the patience to wait a little longer, it can have something better.