NEW YORK (TheStreet) -- Greece faces yet another deadline today to submit new austerity proposals, but it's difficult to say what the nation will present at this critical juncture, according to Economics Professor Wouter Den Haan of the London School of Economics.

"Both the creditors and Greek government have been very unpredictable," said Den Haan. "Greece is very keen to get a long-term deal. In the past, all of these deals were very short term and the creditors gave them a little bit of oxygen so they wouldn't drown."

A long term deal is essential, the economist said, because Greece needs a credible path toward normalcy and sustainable debt levels in order for its economy to recover.

Hopefully, Den Haan said, the creditors will understand that a long-term deal for Greece is the best option.

Eurozone finance ministers will review the latest Greek plan over the weekend.  Den Haan said the economics of the problem are easier to tackle than the political ones.

"On both sides it seems that politics are dominating," he said, adding, "You cannot underestimate how important the politics are in the different Eurozone countries."

A key issue European officials face is the fact countries like Portugal and Spain have done a lot of austerity too, Den Haan noted, since those nations worked hard and are paying back their debt.

"So it's very difficult for a finance minister to come back to their home country and say, well, we're going to give Greece an easy time, but you guys gotta still keep on working hard and help pay back the debt that we have."

At the same time, Den Haan noted, it is crucial for the politicians to keep Europe together. From the beginning, the Eurozone was more than an economic or monetary union -- there were always political motives behind it, he added.

"Greece is incredibly important in that dimension: It's close to the Middle East, it's close to Russia. So that will make it more likely that even though things are quite desperate now, in the end, European politicians may want to bend over backwards to get a comprise," said Den Haan.

At this critical point, either Greece comes up with a credible proposal, or it's the end of the story, he added, noting that he thinks that European countries today are working on a Plan B in case there is a Greece exit from the Eurozone.