Is science really borderless?

Many times, when we enjoy the happiness brought by foreign science, technology, literature and art, we will sincerely sigh, "Science has no borders." Or "Art without Borders" I remember that when Mr. Yang suppressed Huawei in the United States, he said "Technology without Borders" on a certain occasion. At that time, there was condemnation on the internet, accusing him of being a traitor and having no political consciousness, and so on. Is it wrong to say that science has no borders? I don't think there's anything wrong with it. But is it wrong for him to say so? It must be wrong. This seems a bit contradictory. Let's start with the characteristics of science and technology. The reason why science has no borders is because science is the law of nature, or the wisdom created by human beings on the basis of understanding the law of nature. As long as mankind has mastered the weapon of science and used it to benefit and help mankind, then science itself has no national boundaries and is a good friend of mankind, regardless of nationality, color and race. For example, today, scientists from the United States, China, Britain or other countries have invented a cure for COVID-19. However, we can't ignore that science itself doesn't travel around or report to a certain place. It is in the hands of a specific person, and the people who master it are diverse. If people who master advanced technology are pure scientists themselves, don't care about their nationality, and regard people all over the world as their compatriots, then this technology has no borders. But in reality, more often than not, science has national boundaries, because people who master science and technology have nationality, and may have their own political views and parties. This is why during World War II, the United States used nuclear weapons, while Germany and Japan could not. Therefore, in daily life, it is very naive and stupid to use a simple sentence: science knows no borders. If science really has no borders, there will be no World War I and World War II, and there will be no various struggles in the world, especially in the current situation where anti-globalization forces control and occupy power and discourse power. It is very naive to simply emphasize that science has no borders. Therefore, when we speak at ordinary times, we should not only look at the target, but also look at the background of the times and the goals to be achieved.