Will the UN take the hint?

How will the members of the United Nations respond to their Secretary-General's striking demand for reform of their organization?

After the military events of the past year, they did not need him to warn them that the world is ''perilously near to a new international anarchy.''

But perhaps they did need to hear from the top what the UN seldom tells itself: that it has been falling down on the job, straying far from its own Charter, failing to use its considerable capacity for keeping the peace. And they could show that they are listening by acting swiftly on Secretary-General Perez de Cuellar's call for a special Security Council meeting to consider the problems and solutions he cites.

For the United Nations is only as effective as its members make it. Only they can dispel cynicism about the likelihood of strong specific steps to achieve the ends of reform. Only they can justify the basic optimism Mr. Perez de Cuellar retains because ''we now have potentially better means to solve many of the major problems facing humanity than ever before.''

To realize the potential of the UN's international machinery, confidence in it must be restored. To restore confidence, as the Secretary-General argues, progress must be made on such matters as these:

Forestalling or resolving crises through more timely use of the Security Council and vigorous follow-through on its resolutions;

Ensuring the authority of peacekeeping forces through military strength and explicit guarantees of supportive action by member states;

Improving the Security Council as a negotiating forum through minimizing polarized debate and enhancing working relations among the permanent members.

Here lie promising avenues for defusing future conflicts such as Lebanon or the Falklands - those attempts to attain objectives through force which humanity should have gone beyond. Mr. Perez de Cuellar sees the increasing danger of such ventures in a world with enough nuclear weapons ''to destroy life on our planet''; with vast quantities of ''so-called conventional weapons'' immensely more destructive than in the past; with only second place being given to meeting ''the growing needs of the large mass of humanity.'' He welcomes the response to the situation by young people in many parts of the world.

''Who can say that these gentle protestors are wrong or misguided?'' he asks. ''On the contrary, they recall us to the standards and the duties which we set ourselves in the Charter of the United Nations.''

Think if the coming generation could be persuaded that the UN does live up to its ideals, that there actually is an organization which can settle conflicts without war. All honor to the Secretary-General for not letting his first year go by without doing his bit toward this urgent, soaring goal.