Mr. Tsipras returned to this line of attack in a television address on Sunday evening in which he announced that Greek banks would not open on Monday. Pillorying the European Central Bank for refusing to increase emergency aid to Greek banks, he said the bank’s move “had no other aim but to blackmail the will of the Greek people.”

Viewed from Bulgaria and other poorer countries, however, Greece’s suffering draws only curt comparisons.

When Greece’s finance minister, Yanis Varoufakis, in an early round of negotiations in Brussels, complained that Greek pensions could not be cut any further, he was reminded bluntly by his colleague from Lithuania that pensioners there have survived on far less. Lithuania, according to the most recent figures issued by Eurostat, the European statistics agency, spends 472 euros, about $598, per capita on pensions, less than a third of the 1,625 euros spent by Greece. Bulgaria spends just 257 euros. This data refers to 2012 and Greek pensions have since been cut, but they still remain higher than those in Bulgaria, Lithuania, Latvia, Croatia and nearly all other states in eastern, central and southeastern Europe.

Such statistics have made it very difficult for Syriza to win support for its argument that Greece is suffering a uniquely painful “humanitarian catastrophe” and that fellow European Union countries ought to put up their own money to save Athens from bankruptcy. “Greece is not seen as suffering so much,” said Ognyan Georgiev, an editor at Kapital, a Bulgarian business newspaper. “They have the sea, they have big pensions and they have a life that looks better than what we have.”