Falklands debate: second round at UN?

British and Argentine diplomats are sharpening their knives at United Nations headquarters for a new diplomatic clash.

Whether US mediation efforts succeed or fail, the Falkland Islands crisis is expected by most experts here to be dropped again -- possibly in a matter of days - on the UN's lap.

''Only the UN can provide fig leaves to both Argentina and Britain when the time comes for either of them to settle for less than what it had demanded,'' says one high UN official.

If US efforts to effect a compromise succeed, some form of UN presence on the Falklands until final resolution is reached could help assuage wounded national pride. A token UN military force or administration during a transition period could provide both sides with a face-saving alternative.

Argentine and British diplomats are trying to drum up support for the second round of their confrontation at the Security Council. Round 1 was won by Britain when the council adopted Resolution 502, which called for Argentina to withdraw its troops.

Argentina is trying to get nonaligned nations to support its interpretation of Resolution 502. Its position is that this resolution calls for immediate cessation of hostilities and withdrawal of Argentine troops.

Argentina says it will comply with the resolution and withdraw its troops if the British also comply and refrain from using force -- if the British call their Navy back. Under this interpretation, Resolution 502 has a huge loophole: Argentina would withdraw its forces but could leave its civilian administration and flag on the Falklands.

Britain's view is that Argentina is not free to add meaning to the resolution. It holds the resolution clearly calls for a return to the status quo - return of islands to British control.