By Jeffrey Parker

TAIPEI, Jan 19 (Reuter) - With ever fewer weapons in its strategic armoury, isolated Taiwan is turning to moral persuasion in hopes of shaming arch rival Communist China into easing its diplomatic embargo around the island.

Vice-President Lien Chan, back in Taipei after angering China with a three-continent drive to boost ties with a handful of diplomatic friends, urged Beijing in effect to take its own oft-uttered advice and stay out of other countries' affairs.

Lien late on Saturday assailed China' solitary veto of a U.N. Security Council peacekeeping team to Guatemala to monitor peace accords aiming to end three decades of civil war.

"I feel the Chinese Communists' veto...was a great mistake," Lien said, adding that foreign diplomats "concurred in the view that this behaviour was international blackmail."

"The Chinese Communists have lost all respect toward another country's sovereignty," he told reporters at Taipei's airport.

Lien's comments echoed Beijing's own regular attacks on Western-led efforts to use the United Nations to censure China's policies on Taiwan, Tibet and human rights moves seen by Beijing as unwelcome interference in its internal affairs.

Beijing's veto, its first since it took over the U.N.'s China seat from Taipei in 1971 and the only opposition in the 15-seat council, was seen as punishing Guatemala for its diplomatic ties with Taiwan's exiled Republic of China government.

China, one of five permanent members of the security council, has seen Taiwan as a rebel-held province with no right to sovereign ties since a civil war split them in 1949 and has stepped up a drive to isolate Taiwan's government.

Taiwan has fought back by using its export-driven economic clout to build a formidable military and to finance the generous aid that undergirds its remaining 30 alliances.

The November announcement by South Africa, Taipei's biggest ally, that it would switch ties to Beijing in 1997, came as a rude reminder of China's tightening diplomatic squeeze.

Lien's rebuke added to a chorus of moral pressure on China to stop combining the Taiwan issue with the fate of Guatemala, where a spate of lynchings has continued unabated since the peace accords were signed in late December.

Guatemalan rebel leaders flew to New York on Friday to urge Beijing to rethink its opposition to peacekeepers.

The United States has condemned China's introduction of an "unrelated issue" as an "unfair and unfortunate" penalisation of Guatemala's people.

China's diplomatic noose is being felt on Taiwan, where commentators began questioning Taipei's aggressive push for global recognition after Pretoria's surprise announcement.

"We are facing tremendous pressure on the diplomatic front," a senior government analyst told Reuters on Thursday.

"Communist China can use its power at the Security Council to force Guatemala to make certain concessions," he said. "The Security Council seat is a very powerful weapon."

Tamkang University analyst Chang Wu-yueh said Taiwan could easily maintain 20-30 allies but only at a politically untenable price of "millions or billions of dollars" a year in foreign aid to counter China's own growing overseas largesse.

"This kind of diplomatic competition benefits only these small, poorer countries and does little to change the situation across the Taiwan Strait," he wrote in a newspaper commentary.

"Both sides are engaging in a war that is unreasonable and uneconomical," Chang concluded.

Lien said Taiwan's search for new friends must not stop.

"All of us must go out to expand our relations," he said. "In order to survive and develop ourselves, we must go out."