Most of the Greek’s public debt is held by the ECB, the IMF and other Eurozone countries. Schaeuble ruled out these entities taking a haircut on their holdings.
Greece needs more money, so it is a matter of how to give it more aid rather will it get more aid from the troika. No one wants Greece to fail, but there are political constraints to helping Greece.
The IMF is prohibited from granting loans to countries who have an unsustainable debt burden, and the latest troika tests show just that. More IMF loans are out of the question, too.
There has been talk about buying debt back at reduced prices. The problem with this idea is that it has been out there for quite some time allowing speculators to bid up debt price to front-run the plan. If a real plan is announced, they will buy more raising the closer to par. A debt buyback plan simply will not put a dent in the €30bn more that Greece requires.
Since the obvious ideas have been eliminated by officials or practicality, consider this scenario. Greece issues debt under the auspices of the ESM, which partially guarantees it. This allows Greece to sell €30bn it needs to delay its austerity plan the requested two years.
We will see what happens soon enough.