For the second time in a decade, Syria is discovering the cost of relying on Arab oil countries' largesse for economic development in this era of "no war, no peace" in the Mideast.

Foreign exchange problems, balance of payments deficits and 30 percent inflation are forcing President Hafez Assad's government to cut back on imports and investments, raise controlled prices and generally tighten belts.

It was not supposed to be that way. Indeed, Syria was supposed to be on economic easy street.

After the 1973 Abrab-Israeli war, Syria benefited from considerable in flow of Arab investments. But then the funds dried up, and Syria got bogged down in the 1975-76 war in Lebanon. It took two years of scaled down living before the economy functioned properly again.

Then in late 1978, following Egypt's defection from Arab military ranks, the Arab summit meeting in Baghdad promised Syria between $2.25 billion and $2.5 billion annually.

Although the Baghdad summit consecrated Syria's role as the major state confronting Israel, today's problems are beginning to look like a rerun of Syria's troubles in the mid-1970s.

Some Arab allies never honored their Baghdad pledges, at least not in full. No official statistics are published on this score.

Iraq, the only regular "on the barrel head" contributor, paid up in 1979 and during most of 1980, despite a steady deterioration of relations with Damascus. But Iraq's payments are thought to have stopped after the outbreak of its was Iran, as punishment for Syrian backing of the Tehran regime.

Despite Assad's proclaimed union with Libya last year, even optimists doubt the Libyans have contributed more than $100 million since the Badhdad summit, which set their contribution at a much higher level.

Indeed, Syrians and foreign diplomats alike have a favorite guessing game: estimating the size and frequency of the Arab oil state contributions, generally thought to have netted Syria about $1.6 billion in 1980. Analysts are convinced that Syria will get less this year.

Soviet demands for cash payment on new arms deliveries are believed to represent the major strain on Syria's foreign exchange reserves, variously estimated at $200 million or almost nil. And about 50 percent of this year's state expenditure is allotted to go to defense.

No statistics are published on weapons procurement costs, but businessmen's complaints about difficulties in obtaining foreign exchange for officially approved contract tend to prove untrue the central bank's assurances about its plentiful reserves and balance of payments situation.

Moreover, private imports, which account for about a quarter of Syria's total, are financed through an officially tolerated paralle market where foreign exchange can be purchased at roughly 40 percent more than the official rate of 3.95 Syrian pounds to the U.S. dollar. That additional 40 percent is the inflationary price of relieving the central bank of further demands on its meager funds.

Economists privately estimate Syria's balance of payments deficit last year to have been between $300 million and $500 million -- even after taking into acount $1 billion of remittances from Syrains working abroad.

Pessimists suggest that about $50 million worth of banknotes were printed to fill the gap between that deficit and central bank reserves.

With little or no hard currency to spare -- or in the offing -- Syria has scaled back government imports, budgets and investment programs.

Cutting the cloth to fit the mean is part of Syrian management tradition, which eschews the borrowing from commercial banks that in recent years landed Egypt and Turkey in dire financial straits. Government imports, which increased from $3.5 billion in 1979 to $5 billion in 1980, are expected to be cut back drastically.

Even so, analysts see little reason to be optimistic.

After a real increase in gross domestic product of 10 to 12 percent last year, fueled in part by heavy salary raises in the large public sector, the government seems condemned to taking the price lids off items from telephone charges to disel fuel, which now sells at a third of cost.

No changes are thought likely in subsidies for such politically sensitive staples as bread, cooking oil and rice.

The government is also saddled with unproductive large-scale investments such as a new refinery and a phosphate plant, both of which are long overdue.

Much wealth is tied up in such projects with little or no returns. Many other government-owned indistrial plants are said to be running at below capacity and in the red.

Nor is the cost of maintaining 22,000 troops in Lebanon completely offset by contributions from oil states.

Syria cannot count on revenues from the pipeline linking Iraqi oilfields with the Mediterranean terminal at Banias, on the Syrian coast Knocked out soon after the Iranian-Iraqi war began last September, the pipeline was back in operation for 10 days in December before being shut down again.

Officially, Iraq has made resumption of the pipeline's operations conditional on a Syrian pledge not to reship oil to Iran. But some analysts suspect the pipeline has been knocked out again, since Iraq is thought to need badly the revenues renewed use of the pipeline would produce. They not that despite the war, road transportation operates freely between Syria and Iraq, either directly or through Jordan.