Cuba is open, but the US is locked out

Investors from Asia, Europe and Latin American are eyeing the opportunities in Cuba; however, the US investors are left behind, due to the long history of hostility between the two countries. Would the US investment bring benefits to Cuba? Of course, yes. The US investment would be the same as the investments from other places. However, most of the ordinary people hardly accept to receive investments from a country, they had believed as their enemy for about half a century,  and the central government has to be aware of the public opinions. In this example, we can see that creating an extreme relationship is not a good idea. Having a very close ally needs the government to compromise on many issues and throw the benefits away in order to maintain the good relationship. Having an enemy is also not a wise thing to do. There is no enemy for ever; just like the US and Cuba nowadays, they are no longer hostile to each other, but because of the historical issues, they cannot cooperate with each other easily.