Egypt's leaders see the current Libyan military buildup as part of a broader Soviet plan to encircle Egypt and punish it for its expulsion of Soviet advisers in 1974.
Nor can Cairo remain unconcerned at reports that another of Egypt's Mideast neighbors -- Syria -- is considering moving closer to the Soviet Union.
Fears of Soviet encirclement have been aggravated recently because of pro-Soviet Ethiopia's moves to protest Egypt's use of Nile water. In May, Ethiopia circulated a letter to African countries claiming that Egypt was violating the 1857 Nile waters agreement by beginning to pipe Nile water to the Sinai.
(Egypt is very sensitive about the protest because some 85 percent of all Nile waters come from the highlands of Ethiopia.)
Now that Ethiopia is firmly in the pro-Soviet camp, Egypt is afraid that Soviet advisers, who learned much about Nile hydrology while building the Aswan High Dam, will use that knowledge to cut into Egypt's water supply. Those fears were confirmed when Soviet officials agreed last year to build dams and develop irrigation on the Atbara, Takezze, Dinder, and Beles tributaries of the Nile in Ethiopia.
President Sadat claims that the Ethiopian protest was inspired by the Soviet Union. He even threatened war if Ethiopia tried to interfere with Egypt's supply of Nile water. In this tense atmosphere, President Sadat's firm reaction to threats from another pro-Soviet state becomes clearer.
Egypt's leaders have been concerned for some time by what they see as a Libyan military buildup far beyond current needs.
Indeed, some Egyptian officials see the buildup as part of a broader Soviet plan to encircle Egypt and punish it for its expulsion of Soviet advisers in 1974.
Several weeks ago Egyptian Chief of Staff Maj. Gen. Abu Ghazalah disclosed that Libya now has 2,700 tanks but only 600 tank crews. That means that Libya's small 40,000-man Army has more tanks than Egypt's 400-000-man Army.
The Egyptian government meanwhile has reimposed martial law in the western desert near the Libyan border, as poor relations between Egypt and Libya continue.
Egyptian officials claim a belligerent May speech by Libyan leader Col. Muammar Qaddafi prompted the move. Colonel Qaddafi called on the Egyptian Army to overthrow President Anwar Sadat.
As far as Libya is concerned, Colonel Qadddafi reportedly is so concerned about an Egyptian invasion that he has begun building a $3 billion concrete wall along the Egyptian border. The wall reportedly will stretch from the Mediterranean to the Jaghboub oasis, 187 miles south -- protecting about one-fourth of the Libyan border.
He has even threatened that Libya would join the Warsaw Pact if attacked by Egypt.
This theme is far from new for Colonel Qaddafi, who has been a leader in the Arab world for opposition to President Sadat's peace overtures to Israel. But the timing of the Qaddafi speech is significant.
One Western diplomat believes that President Sadat's decision last month to remove martial law throughout the country, even on the Libyan border, was a gesture to the Libyan leader to lower tension in the area. But Colonel Qaddafi's speech dashed threat can be useful in uniting Libyans, particularly the Army, behind his own increasingly unpopular government.
During the past year, border hostilities repeatedly have threatened to break out. Tension became serious last August when Egypt reportedly was massing troops and equipment on the border. Colonel Qaddafi responded by announcing that he already had mined Libyan oil fields and would blow them up if Egypt attacked.
In November, the situation once again became serious after massive Egyptian military maneuvers in Egypt's western desert again aroused Libyan fears of invasion. Libyan leader Qaddafi's suggestion in December that Palestinian commandos should attack targets inside Egypt, such as the Suez Canal or the Sinai oil fields, further heightened the tension.
Then in April there were reports of a Libyan attempt to assassinate President Sadat by blowing up his plane in the Azores when he returned from a short trip to the United States.