Many people believe that the most serious global problems can only solved by international cooperation. I mostly agree with this opinion because many problems today affect many countries and it is very hard for one country solve it alone.
Firstly, environmental problems is one of the biggest global issue in the world. For example climate change and air pollution affects many countries at the same time and making big problems for people. If only one country try solve this problem, it will not be very effective and the result will be not big. Countries need work together and share technologies for reduce pollution.
Secondly, health problems also require cooperation between countries. Diseases can spread very fast because people travels a lot between countries. If governments cooperate and share informations with each other, it become more easier to control these diseases and protect peoples.
However, some problems still can be solved inside one country. For example government can improve education system, transport and healthcare without help from other countries and they can do it by their own.
In conclusion, even if some problems can solved by one country, many global problems are too big and they needs international cooperation for solve it.