EVEN HAD HE not been asked, President Reagan might have taken the route of a high-level bipartisan commission to help his struggling policy in Central America. The device had gotten him out of tight fixes with both Social Security and the MX. Central America is not the large but fairly defined, plate-sized topic that the other two were thought to be. But policy there is a matter in both contention and disarray. Of current national security issues, this is the one in which the administration's position is most at political risk. Sens. Jackson and Mathias so recognized in their call for a bipartisan commission.

Yesterday President Reagan swung aboard with a vengeance, assuring blinding national and international attention by naming Henry Kissinger as chairman. You remember Henry Kissinger. He used to be a diplomat holding high posts in the Nixon and Ford administrations. He is something else now: a statesman, operator and media personality of global dimensions, a personality and force who arrives (almost anywhere) pushing before him an immense bow- wave of controversy and expectation.

The catcalls are already coming in on the left; there, critics of Mr. Reagan's current policy will have to weigh their instant suspicion of the geopolitical emphasis identified with Mr. Kissinger against their reluctant appreciation of his wheeler-dealer political skills. On the right, where Mr. Kissinger is remembered (and reviled) for his role at the 1980 Republican convention as well as for his policies, there may be even deeper misgivings about his first formal appointment under President Reagan. He is likely to be seen as a policy guerrilla.

To us, the appointment says something about Mr. Reagan's readiness to put the national interest ahead of ideological and bureaucratic backbiting. It says even more about his desperation in Central America, where he has been unable to bring the geopolitics and the local factors into line.

Some might be pleased if the Kissinger commission provided a cover of long-term economic and social dedication for pursuit of a short-term military victory. But it is as cynical to use the commission as a gimmick to pass this year's military aid bill as it is foolish to imagine that it can draw the American public into a Central American "Marshall Plan" for decades to come.

If the commission has a useful purpose, it is to quietly extricate the administration from its own bureaucratic and ideological conflicts and to furnish a more plausible and persuasive way to turn the region's conflicts to peaceful channels. One stands in awe at the interests and personalities in the Reagan administration that must be either balanced or subdued for such a course to emerge. But we think it can be done.