Taking into account these criteria, some of the main countries in the world include:
* China is the most populous country in the world, with a population of over 1.4 billion people. It is also the world's second-largest economy by GDP, and has a powerful military. China has a rich cultural heritage and has been a major center of civilization for thousands of years.
* The United States is the world's third-most populous country, with a population of over 330 million people. It is the world's largest economy by GDP, and has the most powerful military in the world. The United States has a diverse cultural heritage and has played a major role in world affairs since its founding in the 18th century.
* India is the world's second-most populous country, with a population of over 1.3 billion people. It is the world's fastest-growing major economy, and has a powerful military. India has a rich cultural heritage and has been a major center of civilization for thousands of years.
* Japan is the world's third-largest economy by GDP, and is a technological powerhouse. Japan has a strong military and a rich cultural heritage.
* Germany is Europe's largest economy and a major world exporter. Germany has a powerful military and a rich cultural heritage.
* France is a major world economic power and has a strong military. France has a rich cultural heritage and is a major tourist destination.
* The United Kingdom is a major world economic power and has a strong military. The United Kingdom has a rich cultural heritage and is a major tourist destination.
* Canada is a major world economic power and has a strong military. Canada has a rich cultural heritage and is a major tourist destination.
* Australia is a major world economic power and has a strong military. Australia has a rich cultural heritage and is a major tourist destination.
* Brazil is a major world economic power and has a strong military. Brazil has a rich cultural heritage and is a major tourist destination.
* Russia is the largest country in the world by area, and has a powerful military. Russia has a rich cultural heritage and is a major world economic power.
These countries are all major players in world affairs and have a significant impact on the global economy, politics, and culture.