A growing number of countries now offer immigrant investor programs, exchanging residence rights or citizenship for a sizeable investment in their economies. From "cash-for-citizenship" to incentives to invest in private sector businesses or property, the market for investor immigration has become increasingly diverse. 

The idea with a second passport is that no government should have the sole power over your life or your assets. If you are the citizen of only one country, as most people are, you are essentially at the mercy of your government. If they decide to harass you or confiscate your assets, most of the time you are on your own, unless you are a citizen of another country. Owning a second passport through dual citizenship in another country is an integral part of international diversification.