AS YOU CAN SEE from today's Letters to the Editor, not everyone agrees with our comments earlier this month on a request by Iranian students for a permit to rally in Lafayette Park on Dec. 8. To be sure, we do not contend that aliens should be permitted to commit violent acts in this city; but neither do we accept the notion that foreigners with valid visas are somehow denied the protections under law that our own citizens enjoy. Indeed, we were pleased to read this week that the National Park Service has now reconsidered its position and will allow the students to rally in the park on Dec. 31 and Jan. 1.

Apparently the Park Police - who weren't properly prepared for the bloody protests and counterprotests that erupted here during the November visit of the Shah of Iran - no longer object to another rally; neither does the Secret Service, which had joined the Park Police in urging that the previous request be denied. Park Service officials are now saying that a "sufficient cooling-off period" will have passed by Dec. 31 to minimize a recurrence of violence.

Though we disagreed with the previous denied, we see no reason at this point to argue about the explanation given for the officials' change of heart. The latest action by the Park Service is not only welcome; it is also in keeping with this city's tradition of according demonstrators the fullest freedom consonant with public safety. That has been the policy of the Metropolitan Police Department, which did allow the Iranians to amrch through downtown Washington on Dec. 8 - without incident.

That said, in no way do we mean to belittle the possibility of incidents occuring at the next rally - or, for that matter, at any other rally in the future.On the contrary, the Park Police would do well to take a cue from the Metropolitan Police this time and preapre with equal vigor and sensitivity to protect the rights of all parties involved - alliens as well as citizens.