Prime Minister Shimon Peres denied today that Israel has any intention of attacking Syria, but he warned that Syria is at a crossroads in its support of international terrorism and should be cautious because of changing world attitudes toward terrorist activity.

Speaking on Israeli radio on the country's 38th anniversary of independence, Peres also reiterated that he sees no signs that Syria is preparing to attack Israel, at least in the near future.

"Syria must be very careful in their engagement in international terror," Peres said. But he added that "we have no plans to attack Syria" and said his government would continue to work toward peace "uninterruptedly."

His statement was the latest attempt by senior Israeli Cabinet ministers to reduce what Peres called "verbal tension" that grew in a week of clamor in the Israeli press over bellicose statements made here and in Damascus, and over disclosures that for several months Syrian Army engineers have been building fortifications and emplacements for guns and tanks in southeastern Lebanon, just above the Israeli-declared "security zone."

Although Israeli officials confirmed that Peres had asked the United States to convey Israel's concern to Syrian President Hafez Assad over the new fortifications, informed sources said that the concern has been tempered by the fact that no Syrian combat troops or weapons have been moved into the fortifications, and that the sites could merely be standby positions to which troops would be moved if necessary.

Israeli Army officials said the earthworks construction is in the area of Lake Qirawn that was vacated by the Israeli Army a year ago when it withdrew most of its forces from southern Lebanon. At the time, Israel warned Syria not to attempt to move into the area.

One senior Israeli military source privy to Army general staff discussions characterized the new fortifications and emplacements today as "defensive," saying they were intended to enable Syrian forces to move quickly to prepositioned strongholds in the event of an outbreak of hostilities, and by themselves are not a major security threat to Israel.

However, the source said, they also could be used as a springboard for an attack. "This adds up to another power move to improve their position on the ground, but by no means does it mean war. What it means for us is a shorter reaction time," he said.

Another expert on military strategy and national security, Hebrew University political scientist Dan Horowitz, said that the Syrians regard the new fortifications as defensive, but that even if they moved a combat division into the vacant emplacements, it would be better from Israel's perspective to have the division deployed there than on the Golan Heights.

Citing "alarmist tendencies" in both Israel and Syria, Horowitz said that since the surprise Arab attacks of the 1973 war, Israel has "tended to interpret any change in deployment as a threatening one," while Syria has become increasingly nervous since the U.S. attacks on Libya and U.S. and Israeli allegations of Syrian support of international terrorism.

"So each side is taking precautionary measures that might be interpreted by the other side as a threat or danger of imminent attack, which I believe is not the situation. There is no strategic rationale for either side to initiate hostilities," Horowitz said.

The buildup of "war fever" here began early last week with statements by Israeli Defense Minister Yitzhak Rabin in Washington accusing Syria of supporting international terrorism and citing the attempt last month to blow up an El Al jetliner in London. Although Syria has repeatedly denied involvement in the terror attacks, three Syrian diplomats were expelled by Britain after they were alleged to have had a role in the attempted El Al bombing.

On Thursday, CBS News, quoting "reliable sources," reported that Rabin had told U.S. officials that Israel was going to retaliate against Syria. CBS also quoted "Israeli military experts" as warning of a rapidly growing Syrian threat and saying that the sooner Israel moved against Syria, the better off it would be.

The Syrian reaction to Rabin's allegations and the press interpretation of what they portended was sharp. The official daily, Tishrin, warned of an imminent Israeli attack, and Syria's head of intelligence in Lebanon, Army Brig. Gen. Ghazi Kinaan, was quoted on the Voice of Lebanon radio as predicting an Israeli attack within a week. Assad was quoted in the Kuwaiti press as warning that "the cannons of Israel are pointed at Syria."

Played back in the Israeli newspapers and television, the Syrian reactions appeared to enhance the atmosphere of imminent war, so much so that Peres on Monday said that rhetoric had reached a point where one Arab country had appealed to Israel not to bomb refugee camps in Lebanon. Peres did not identify that country, but it was widely believed to have been Egypt.

Friday, amid criticism by some Cabinet ministers that Rabin had engaged in reckless saber rattling, Peres began attempts to play down the threat of war, blaming the "verbal tension" on the Palestine Liberation Organization, which he said was spreading rumors of an imminent Israeli attack to cause confusion in the region, and the press, which he said was exaggerating the tension.

"We have no plans to attack Syria -- not today and not tomorrow -- and no one will drag us into a war that we don't want. I wouldn't want us to find ourselves in a war due to media escalation," Peres said in a speech in Tel Aviv on Friday.

By Sunday's Cabinet meeting, Peres, Rabin and the Army chief of staff, Maj. Gen. Moshe Levy, all were issuing calls to discuss the Syrian issue in a more sober fashion.

Since his return to Israel, Rabin appears to have gone out of his way to make a distinction between the need for Israel to combat terrorism sponsored or initiated by Syria and the danger of a military confrontation between the two.

"Our policy is clear," he said: "We want to prevent war. We do not have any intention of initiating a war, but we must guarantee by greater alertness and preparedness that there will not be a mistake on the part of the other side, and do this in a way that will not lead to escalation."