SEVERAL YEARS ago, a Fairfax County official joked that establishing regional cooperation with the District would go about as quickly as establishing diplomatic relations with Communist China had. Actually, the local effort is beating the record of the international one. The suburbs are developing ties with the D.C. government in an effort to reduce unemployment here.

Officials in Alexandria, Arlington County, Fairfax City, Fairfax County, Falls Church and Loudoun and Montgomery counties have announced that they will join the District's regional jobs plan. This began as an effort to match unemployed D.C. residents with unfilled suburban jobs, mainly in Fairfax County. The agreement leaves Prince George's County as the only really close-in jurisdiction that has not joined -- but more on that in a moment.

Despite significant demographic differences, Montgomery and Prince George's counties share the lowest unemployment figures of the jurisdictions closest to Washington. Unemployment figures in each of the three closest northern Virginia localities are higher. Joblessness in the District is higher yet.

District Mayor Marion Barry says the city will spend about $300,000 to recruit, refer and transport its workers to suburban jobs. The Washington Area Jobs Council has been formed, and workers from the District and the suburbs will be able to take advantage of services ranging from job training to day-care provisions. The other jurisdictions have not determined their financial commitment to the plan, nor the services they will offer.

In any situation such as this, in which leaders from so many jurisdictions are vying to get the best possible benefit, some friction is going to occur. There has already been some rather spirited and unfortunate name calling ("He's the biggest flannel-mouthed Irishman I've met . . . "). But that Irishman, Alexandria Mayor James P. Moran Jr., had raised a legitimate concern. An initial proposal would have opened surburban jobs to District workers alone, while Alexandria, with the second highest unemployment figure in the Washington area, would not have benefited.

Prince George's County officials raised the same concern, but the latest proposal would also allow unemployed suburbanites to take advantage of the plan. That was good enough for Mr. Moran. It should have been good enough for P.G. officials as well, who do their workers and themselves no good by not taking part in what could be an important test of regional cooperation. It is a plan that could significantly reduce the District's eight percent unemployment rate, while giving rapidly developing jurisdictions such as Fairfax County the employee resources they need.