Well, it would be another great leap for humans to finally start their first colony on another planet. But considering our history and how colonies tend to get independent why would an organisation of any kind ever risk and put money into creating this colony when it could totally get out of hand?

Let's assume:

 - A colony on mars is created which is **stable enough for normal life** and human reproduction
 - This colony is able to grow and produce **food and get enough water** (from polar ice caps probably)
 - There are nearly intact resources on Mars (Mines, Land, ...) 
 - Other nations on Earth are not able to easily travel to Mars for an attack or conquering other parts of Mars
 

Therefore could we conclude that:

 1. There is no specific reason for this colony not to cut ties with Earth and therefore it's a high risk to finance this colony
 2. We will wait then until it's low cost to travel to Mars and that planet will experience multi nation governments and probably wars over the planet's resources