NEW DELHI, JULY 23 -- When the sounds of the Israeli national anthem wafted over the closely cropped grass of the Delhi Lawn Tennis Association courts this afternoon, the young men sweating in the intense heat of India's summer seemed to give it no more than passing attention.

For the Israeli Davis Cup team, holding a last practice session for Friday's quarterfinal opener with India, the anthem is a familiar sound.

For India, it is anything but familiar.

India has long shunned relations of any sort, including sports, with Israel in an apparent effort to win friends in the Arab world and blunt the advantage its Moslem neighbor and enemy Pakistan might have with those prospective allies.

But some gentle persuasion by veteran Indian tennis star Vijay Amritraj contributed to a decision to allow an Israeli team to come to India for the first time in two decades.

That India would been barred from Davis Cup play for three years and fined $10,000 if it didn't play also may have had something to do with the final decision, along with the anticipated advantage of playing on familiar grass courts in the 100-degree-plus heat of an Indian July.

Whatever the reason, sports won out over politics, although more than one Indian political commentator has noted that maybe India and Israel have a common interest in stopping Pakistan from producing a nuclear bomb, as it reportedly is on the verge of doing.

Indian spokesmen say New Delhi's support for the Arab cause remains unchanged, and the PLO's Yasser Arafat will arrive here Monday for an official visit -- while the Israeli team is scheduled still to be in town, a world-class scheduling snafu.

Nor will politics be far from view when Ramesh Krishnan and Shlomo Glickstein open the series Friday on the center court of the DLTA stadium.

Responding to reports of threats by a Palestinian terrorist group and possible political demonstrations, the DLTA oasis of green in a crowded residential area of the Indian capital has been turned into an armed fortress.

A 10-foot-high tin fence blocks the view from the street. Police armed with automatic weapons are stationed in watch towers and at the gates. Everyone entering the complex will be frisked. More armed police patrol the wooded park behind the tennis complex and marksmen can be seen on the roofs of nearby houses.

"The stiff security doesn't bother us. We are used to it," said one Israeli official.

Amritraj, who has represented India in international competition for a decade and a half, also shrugged off the intense security.

"Once you're on the court, you forget everything else. You're more interested in getting your shots in," he said after the pairings were announced this morning.

Almost lost in the politics of the event is that world-class players will be competing in the Indian capital. Also playing for Israel will be Amos Mansdorf and Gilad Bloom. Completing India's team are Amritraj and his brother, Anand Amritraj.

Indian tennis experts are confident Vijay Amritraj can win both his singles matches and hope that Krishnan can beat Glickstein. They tend to concede the doubles to the Israelis.

After the opening Krishnan-Glickstein match, Vijay Amritraj will play Mansdorf, perhaps the most interesting matchup of the series. Barring last-minute changes, the Amritraj brothers will play Mansdorf and Bloom in the doubles Saturday and the reverse singles are scheduled for Sunday.

"We can win it, I'm sure," said one young DLTA coach this afternoon as he watched final touchups on the center court.

But a hint of doubt entered his voice when he began talking about Mansdorf.

"He's very quick on his feet and he has very good strokes," he said of the 21-year-old, who is in his first full year of professional play. Mansdorf took France's Henri Leconte to five sets last month at Wimbledon before losing.

Joseph Stabholz, the Israeli captain, says he gives the Indian team a 60-40 advantage because it is playing at home.

Of Israel's last four Davis Cup series, only one was at home, against Belgium. The Israelis beat the Netherlands, Switzerland and Czechoslovakia away, with the victory over the Czechoslovakians considered a major upset.

India defeated Argentina in the first round in March to reach the quarterfinals.

For Yashwant Singh, the secretary of the DLTA, preparations for the series have been anything but simple -- but then nothing in India ever is simple.

"There are so many egos to keep satisfied," he said in a moment of gentle exasperation.

One maxim of Indian life is that everything usually tends to work out, even if it usually is at the very last minute and doesn't come about exactly the way it was planned.

Proving the point was the belated arrival late this afternoon of spiffy uniforms for the ball boys. They finally had cleared New Delhi's notoriously sticky customs officers.