If a "Grexit" (Greece leaving the euro zone) happened, Greece would face a long-term closure of banks with capital controls and withdrawal limits, and depositors would lose at least 50 percent of their deposits for two reasons: First, under a Grexit, the Greek banks would go bankrupt and a de facto haircut (loss) on deposits will be imposed. Second, depositors would face further losses in the conversion to the new currency and inevitable subsequent devaluation. Unemployment would skyrocket. Importers would face huge hurdles and there will be significant shortages. The new drachma would be a heavily devalued weak currency resulting in inflation and widespread poverty as Greeks would afford only half or one-third of their present purchases. Greek politicians would print large amounts of new drachmas, further increasing inflation, and nullifying any benefit to exports from the devalued new drachma.

Read MoreOp-ed: Greece has only one option

Greece would shift from being part of Europe to a weak poor country at the mercy of the big powers of the region — especially Turkey. Its territorial integrity would be challenged.

