The first reason: the history of bringing dollars into international currency.
Starting from the Bretton Woods agreement after World War 2 whose effects are still felt to this day; agreement to use gold as a global standard currency value. At that time the economic situation of the world countries except the United States, destroyed by war. This causes them to rely on loans granted by the United States. This loan is given in the form of U.S. Dollars. As collateral, the American-owned gold received these countries. The result, America ruled the automatic gold in the world and it was only worth U.S. dollar backed by gold. In practical terms, this means the U.S. dollar has replaced gold as a source of liquidity into the global economy and world financial system basis. By implication, every country build reserves in the form of U.S. dollar; dollar reserves necessary for the country's currency can be exchanged with the corresponding dollar or gold. At this time is that the American currency becomes an international currency.
The second reason: the risk becomes an international currency
Not always be an international currency that have a positive effect on countries that have currencies that, in this case American countries with the dollar. Many negative effects that could hit the U.S. as their currency becomes an international currency. Some negative effects become an international currency, among others:
1. The country must maintain trust, which causes the country to have a tough task for the world.
2. If the owner of an international currency can not maintain a trust, it can cause the currency drop suddenly.
3. Will be more difficult to control liquidity
The third reason: not all that strong currency can become an international currency
To become an international currency needs a strong owner, in this case a strong state. Being a strong currency is not being able to become an international currency. This is because countries with currencies that do not necessarily have the economic and political stability is good. And to become an international currency, the country needs political and economic situation stable, because as an international currency is needed trust of the world for the world to use it.
For example, the currency of the country Iraq, the Dinar. Although the current dinar as one of the strongest currencies, but the Iraq situation is not stable, due to war, the conflict in the country, and its economy. This causes the world does not want to entrust the dinar currency to Iraq because even though it's strongest currencies, but not necessarily in the long run will be stable. Be unstable due to the intensified war-so or domestic conflicts which in turn can lead to impoverished countries and their currency fell to the weakest currency. Whereas the currency exchange and store it is a long-term activities, which required great trust of the world. This is because the U.S. dollar became the currency of the world believed that conditions can be predicted that the country will be stable in the long run.
