Questions about the future of the euro due to tensions between the weak and strong economies within it caused the currency to fall to a two-year low against the dollar last week.

Remember, the United States is going through quantitative easing as a method of inflation so its currency should be weakening against the euro. Instead, it's getting stronger, showing the impact that the PIIGS are having on market confidence.

The truth is that the euro was badly constructed from the beginning as it took no account of national economic situations. In the mid-2000s, friends used to ask me when the property market would stop its upward spiral. My answer was always the same: when Germany recovers.

Ireland's economic boom ended in 2001. People forget that we ran out of money and had a property crash. The global economy was slumping but low interest rates were introduced after 11 September, a contributor but not the main one to the global downturn at the time, and the great Irish credit binge began.

Low interest rates had no place in the Irish market but the rate was being fixed in Frankfurt by the European Central Bank and we gorged on the excesses. Now though, we are paying for that more than we should have to because of a German recovery.

The truth is that the future of the euro, if there is to be one, lies in creating a three-tiered interest rate for governments in the eurozone.

Countries in pre-agreed growth phases would have to pay a higher rate and place a certain percentage of their budget excess into a sovereign wealth fund to stop their economies overheating.

Second-tier countries experiencing more modest growth would borrow at a more reasonable rate and the third tier would be those desperately in need of cheap money. That would be us and Greece, and potentially Portugal, all of whose recovery is threatened by borrowing at interest rates that will only serve to prolong our economic misery.

Without an ability to secure cheap money, Spain in turn will be targeted by speculators and if it falls then it is hard to see a future for the eurozone.

Murmurings last week were that Belgium could be next. Eurozone members are being lined up as dominos, largely because of German indecision. Its chancellor Angela Merkel needs to make decisive policies now or the single currency is bound to fail.