The Serbian government, already grappling with hyper inflation, certainly believes the embargo is taking its toll. Radoje Kontic, a deputy prime minister in charge of the economy, said the removal of the sanctions was a priority because otherwise 'a total collapse is inevitable'.
The Serbian Academy of Arts and Sciences has written to the UN Secretary General to say that 'the Serbian people have been brought to the edge of existence' by the sanctions and that 'children and the sick are dying'.
While such statements may be exaggerated, hard evidence that the embargo is working lies in the acute shortage of petrol for private use in Serbia. Streets in Belgrade that were once filled with traffic until late at night are often deserted. The government has slashed petrol supplies to residents of the city to conserve fuel for the armed forces. Petrol is available for hard currency, but that in turn suggests that the sanctions have caused the black market to expand.
Until early this month, oil was arriving on barges - some Serbian, some from other nations. They collected supplies at the Romanian port of Constanta and sailed up the Danube into Serbia. With no international body patrolling the Danube, and no monitoring of invoices and end-users, sanctions-busting proved relatively easy. The West then put pressure on Russia and Romania to cut off this source of supply, and experts said both countries have fallen in line.
Boris Yeltsin, the Russian president, signed an order on 14 July on strict implementation of the sanctions. It was not necessarily the Russian and Romanian governments that were breaking the UN embargo, though they have proved more reluctant than the West to isolate Serbia. Rather, the guilty parties were individual companies and traders cutting deals with Serbian organisations.
Some German officials have suggested that Greece - a traditional friend of Serbia - has also violated the sanctions, but if so the amounts involved are probably small. Greece has no common border with Serbia; its goods must first pass through Macedonia. But Macedonia, still seeking diplomatic recognition from the West, has no interest in turning a blind eye to sanctions-busting.
Some goods may be entering Serbia by sea through ports on the strip of Adriatic coast that belongs to Montenegro, Serbia's ally. This is the region where the Western European Union and Nato have deployed warships to enforce the embargo. However, the Western operation is not authorised to stop ships or check their cargoes.
According to Italian officials co-ordinating the operation, about 50 to 70 merchant vessels pass through the Strait of Otranto everyday. Before the embargo, Western businessmen said some vessels were unloading goods at Montenegrin ports, from where they were taken to Serbia.
With the world's eyes on Serbia, less attention has been paid to Croatian violations of the UN arms embargo on the former Yugoslavia. By air, sea and land, Croatia has received tons of weapons in the last year. Much weaponry is of Soviet design and comes from former Warsaw Pact countries. Some have arrived via Austria, not from the government (although it supports Croatia), but from underground arms dealers.