Vienna — This is a critical period for Yugoslavia. It is struggling with a huge foreign debt - and getting some relief. And on the political front, a rotation of its collective leadership - and the first overhaul since Josip Tito - is just around the corner.
After some of the toughest austerity pressures ever exerted on a client nation, the International Monetary Fund has finally agreed to help Yugoslavia with its $21 billion debt to Western creditors.
A ''letter of intent'' due to be signed March 15, qualifies Yugo-slavia for a one-year IMF standby credit of $400 to $500 million. The IMF agreement, in turn, opens the way for a financial aid package from Western governments.
Yugoslavia will make some but not all of the economic adjustments demanded by the IMF. Initially, the IMF wanted Yugoslavia to bring interest rates in line with inflation (currently at 60 percent), to scrap its six-month price freeze, and to devalue the dinar by 18 percent.
In the event, Yugoslavia gained its three major points: It has until mid-1985 to adjust interest rates; only part of the price freeze is to be removed here and now; and devaluation will be gradual.
Politically, the IMF agreement is a satisfactory one for Belgrade. It wards off an immediate blowup that the austerity measures might have sparked from the already hard-pressed Yugoslavs. And in the process, the federal government seems to have held at bay both regional rivalries and hard-line demands for a return to ''real Marx'' and centralization.
In the political arena, a new state presidency is about to take over. This is its first virtually complete change of personnel since its creation by the late Tito.
The aim of the collective leadership was to forestall the potential fissures among the republics and autonomous provinces. But those rifts have occurred anyway in the last two years as the economy has stagnated (although some industrial improvement has just been reported).
The presidency has eight members, one from each of the six republics and two autonomous provinces. All but one are retiring this year to make way for the new collective leadership. Many younger Yugoslavs saw this year's change as a chance for far-reaching rejuvenation. But this implies some substantial adjustment of the power-managing system itself.
Although the new collective leadership does not bring really new faces, its average age, 61, is six years younger than the previous presidency. Several, however, have held senior Cabinet posts.
To that extent, therefore, the new team is both experienced and somewhat younger. Its test will be if it shows understanding for the demands of a younger generation of Yugoslavs. These people - many of them apolitical managers and technocrats - want both political and economic reform to carry Yugoslavia's brand of democracy a step further.
While the economy is being straightened out, however, ''liberal'' ideas such as pluralism in place of the party's monopoly of the presidency and all other key seats of power will likely be shelved.
But such ideas do have supporters in the party's top leadership already.