Eurozone finance ministers struck an unprecedented deal before daybreak for a bailout that is to cost about 310 billion dollars, and which markets greeted with muted relief.
Economists and others were quick to note that a modern Greek odyssey had just begun, and that the new 2020 target of getting the national debt down to 120.5 percent of output might be beyond reach.
In Greece, commentators stress that the conditions make Greece subject to intense eurozone monitoring.
The euro jumped in early trading in Europe, but then gave up half its spike to trade around 1.3237 dollars, from 1.3185 before the deal. Europe's main stock markets drifted lower.
European Union leaders hailed the deal and Greek Prime Minister Lucas Papademos declared himself "very happy" with the deal which includes a huge debt-write down by banks and insurance groups, while local newspapers pointed to bleak austerity ahead.
Like mythical Hercules ordered to clean out the Augean Stables, the country faces the task of clearing a debt pile of 350 billion euros, with an economy that has not grown since 2007.
But Luxembourg Prime Minister Jean-Claude Juncker was able to proclaim an agreement to "secure Greece's future in the eurozone" after 13 hours of talks in Brussels between governments, the EU, the IMF and private creditors.
"A marathon meeting in the never-ending marathon of the eurozone debt crisis," ING senior economist Carsten Brzeski commented.
EU Economic Affairs Commissioner Ollie Rehn agreed with the marathon metaphor, and added that the deal "is an essential step further for Greece and for the euro area as a whole."
Like Juncker, Rehn underscored that "this programme is supported by a very substantial contribution by the private sector."
Juncker, head of the Eurogroup of finance ministers, said that "up to 130 billion euros until 2014" in loans from Greece's currency partners would be dependent on the write-down of a nominal 53.5 percent of privately-held Greek sovereign debt.
Negotiators for the banks said this should deliver 107 billion in savings to Greece.
The Eurogroup will decide whether this exchange of devalued old bonds for new IOUs on rewritten terms has been "successful" in early March, Juncker said.
Papademos, a former European Central Bank (ECB) vice president backed by EU partners to lead an emergency coalition government in Athens, acknowledged that full delivery of the deal depends on Greece delivering on multiple conditions in "a timely and effective manner."
But, he maintained: "I'm convinced that the government after (an April general) election will also be committed to implement the programme fully... because it is in the interests of the Greek people."
There were nonetheless also voices of caution and reminders that the deal cannot provide a magic solution.
"Even with this agreement, most of Greece's problems lie ahead of it, not behind,' said Brussels-based analyst Sony Kapoor.
The financial lifeline remains contingent on a string of Greek economic and legal reforms to be implemented by the end of the month, and the "permanent" presence of EU and IMF officials in Athens to run the rescue programme.
"It is a very good agreement and I welcome the commitments of the Greek government to restoring growth and stability," said ECB chief Mario Draghi.
He stressed that compliance with the deal "must be rightly monitored."
Athens faces debt repayments of about 14.5 billion euros on March 20, and this deal was intended to avoid national bankruptcy.
The agreement "provides a comprehensive blueprint" for fixing Greece's public finances and "safeguarding financial stability" throughout the eurozone, a Eurogroup statement said.
Greek government accounts are required to reach "primary surplus as from 2013" and a officials must press on with a privatisation drive worth at least 50 billion euros, the Eurogroup statement added.
Athens is also expected to quickly anchor in its constitution a provision for "ensuring that priority is granted to debt servicing payments," possibly a blocked account to protect public lenders' interests.
The International Monetary Fund said it will fix its contribution in March, by which time the eurozone is also set to boost a financial firewall to 750 billion euros.
Meanwhile, eurozone national central banks agreed to contribute via their own write-down of Greek bonds, but a report by creditors said Greece would still need 245 billion euros in bailout aid by 2020, eurozone sources said.
Eurozone hardliners' patience with Greek politicians, facing an election in April, almost snapped in recent weeks and following the failure of an initial 110-billion-euro EU-IMF rescue nearly two years ago.
But as Brzeski at ING said of the agreement reached overnight: "It looks like a deal, it walks like a deal, it is almost a deal."
