TODAY IS May Day, the international revolutionary holiday. The origins of the celebration are somewhat obscure, but it may have started in 1886 in the United States with a national union drive for an eight-hour working day.

At any rate, the holiday was firmly entrenched in socialist tradition by the turn of the century, when growing European labor unions would stage one-day general strikes to demonstrate their solidarity with progressive forces around the world. Since then, the holiday has come to symbolize the aspirations of the world's people to live in peace, freedom and dignity.

May Day has a special significance this year. With the signing of the January peace agreement, the people of Vietnam moved closer to their goal of constructing a humane and just society. The United States government for the first time officially recognized the sovereignty of Vietnam, and pledged to cease its interference in that country's internal affairs.

But war continues in neighboring Cambodia. The Nixon government should follow its Vietnam initiative and end its criminal interference in the Cambodian revolution -- a struggle which, like its Vietnamese counterpart -- is yet another attempt to achieve the ideals May Day symbolizes.