If you feel like you know what’s what, then I encourage you to make an economic argument. Going all Jack Bauer, “Millions of people are GOING TO DIE!”, isn’t an economic argument.
Yes, maybe a large number people will die of starvation. But let’s take the example of inoculation. When you give someone a shot to immunize them against a virus, some percentage of the people who get the shot actually contract the virus from the shot (since inoculation is a weak version of the virus), and some of those people die. By inoculating, you are actively and knowingly killing people. But you still do it because you know that the alternative would be that an even greater number of people die.
So I could explain to you what Greece could and should do, but instead I’m going to tell you that you’re championing the side of greater destruction, death, and hardship. Don’t do that.