France and Germany are emerging as the crucial backers of any lifeline for Greece, but they have slow growth and budget troubles of their own — deficits equaling 6.3 percent of gross domestic product in Germany and 7.5 percent in France. And among voters in both countries, “there is very little appetite for rescues,” said Marco Annunziata, chief economist for Unicredit.

The most vulnerable country after Greece, some analysts say, is Spain, which has been mired in a deep recession. Facing an unemployment rate of 20 percent, a budget gap of more than 10 percent of gross domestic product, and an economy expected to shrink by 0.4 percent this year, Madrid has little wiggle room if investors shun an expected 85 billion euros in new bond offerings this year.

Spain’s neighbor Portugal is also vulnerable. Large budget and trade deficits, combined with a shortage of domestic savings, leave Portugal dependent on foreign investors. And, as in Greece, there may be little political will to slash spending or raise taxes.

Image Pensioners demonstrating Wednesday in Athens. Greece announced new measures meant to improve its economy, among the most troubled in Europe. Credit... Petros Giannakouris/Associated Press

That’s in sharp contrast to Ireland, which had been a source of anxiety last year. New austerity measures, including a government hiring freeze and public sector wage cuts, have put it in a stronger position as it raises 19 billion euros this year.

The Italian government is also heavily indebted — it has more than $2 trillion in total exposure — but it is also in a slightly stronger position than Spain or Portugal because its economy is expected to grow by 0.9 percent this year and 1.0 percent next year. In addition, its budget is not as far out of whack, with the deficit this year expected to equal 5.4 percent of G.D.P.

According to Kenneth J. Heinz of Hedge Fund Research, the big hedge funds are now evaluating the response by other European countries in extending a lifeline to Greece before they probe weaknesses and opportunities in other countries.