Sudan, Egypt's neighbor and closest remaining ally in the Arab world, has recently experienced grave unrest and spiraling political and economic woes.
Sudan's veteran President Jaafar Nimiery appears to have survived a series of crises since the beginning of 1982. And significantly, Saudi Arabia is among the governments that have come to his aid. The Saudis had previously kept some distance from Nimiery because of his support for President Sadat's peace initiative with Israel.
But problems remaining in his debt-ridden Arab-African nation seem almost as vast as its sprawling 96,000 square-mile landmass. And Nimeiry's own unpredictability during his 13 years in office, as well as the close link between events in Sudan and those in neighbors Egypt and Libya, means that analysts are watching developments in Sudan closely.
''Nimeiry has been a real friend to the United States in his foreign policy, '' says one State Department analyst. ''His problems are in the economic and domestic policy fields.''
Those problems flared anew at the beginning of the year, following the government's announcement of price rises on several basic commodities. The problems are reflected in:
* Student riots at the three universities in the capital, Khartoum, which broke out almost immediately on the heels of the price hikes. The riots built up to the point where authorities had to close the universities and send the students back to their hometowns.
Nimeiry blamed unnamed Arab nations for provoking the disturbances. This was thought to be a reference to Libya, whose leader, Col. Muammar Qaddafi, has been calling for Nimeiry's overthrow for years.
* A stormy dispute between Nimeiry and critics in the leadership of Sudan's sole party, the Sudanese Socialist Union (SSU), toward the end of January that led the President to threaten to resign, according to reports.
* Escalating disturbances as January wore on, with factory occupations and strikes starting to hit at Sudan's already chaotic economy. But Nimeiry hung on to power and on Jan. 25 he announced a major purge of opponents and suspended the work of the SSU.
* Nimeiry targeting in the purge his own armed forces commander in chief, vice-president, and minister of defense, Gen. Abdul Majid Hamed Khalil. The President stripped Khalil of all his powers and placed him under virtual house arrest. Nimiery subsequently named himself minister of defense.
Some reports say Khalil had voiced Army demands for a cleanup of the SSU and of government corruption. Others say he had been plotting to kill Nimeiry, but that the plot was discovered just in time. These sources said 250 officers were arrested along with Khalil.
* Unrest continuing despite Nimiery's crackdown. The President has so far refused to placate critics, promising further price rises instead. On Feb. 7 a newspaper in Beirut reported that a group of soldiers had stormed the President's house, trying to kill him.
The evolving spiral of criticism, purge, and presidential isolation has led to comparisons with what occurred in the last weeks of President Sadat's rule in Egypt. Developments in the two Nile neighbors have been intertwined for more than 160 years.
Nimeiry was one of only three Arab leaders who refused to break off relations completely with Sadat following the latter's peace treaty with Israel. He was perhaps repaying a political debt to Egypt, incurred when Egyptian troops saved his regime from reported insurrection in March 1970.
The Muslim Brotherhood has received a boost from the huge growth in influence of its counterpart in Egypt.
Communists lost some political ground throughout much of the '70s, but the latest economic problems might give them a new chance to capitalize on their longstanding bases inside the Sudanese labor unions.
Looming behind Sudan's current instability is the specter of $5 billion of national debt, with payments on up to $2 billion of that recently falling in arrears. Prospects for speedy repayment are dim, with major moneymaking projects in cotton and sugar production in chaos.
The private banks involved in Sudanese debt financing agreed in January to roll over loans until at least the end of the year. And the International Monetary Fund provided the backbone for what one official called ''this house-of-cards-like arrangement'' at a meeting Feb. 18. The IMF will lend Sudan governments have put together a second aid package of $350-to-$400 million over the next few months. The Saudis also agreed in February to provide Sudan with three months' oil supplies free of any charge.
But this gives Nimeiry only a short respite. It remains to be seen whether he can pull his finances into even minimum shape required by the IMF while staying in power.