There are no international patents, only international patent applications, called PCT applications. The application can be filed in the patent office of a country. After the international publication, you can choose which countries will enter the national phase. The specific authorization or not shall be examined by the country applying for entry according to its own patent law. The patent right obtained is also the domestic patent right of each country that enters. PCT application only means that applicants don't have to go to all countries to apply once.
For example, if you applied for a patent in China, before the patent was published, someone in the United States produced this product, so you can't sue him. Because you didn't apply for protection in America. If you apply for PCT, choose to enter the national phase of the United States in the future and finally get a patent right in the United States, then you can sue him according to this patent right.