Most people would agree that English is an important language for international business. There are more speakers of English as a second language than of any other language in the world. However, the idea that English is the international business language most likely comes from a Western perspective.
Billions of dollars in imports from Asia are bought each year by North American companies. Also, many Western companies now have their own products made in Asia. With Mandarin being the most widely-spoken language in the East, it's possible that it will soon be considered equal in importance to English.
An increasing number of people are learning Mandarin as a second language. It has become a huge plus for those seeking jobs in international business to be able to speak it. Mandarin is a difficult language to learn for many, especially the writing system. Therefore, those who speak Mandarin as a first language may have an advantage over those whose first language is English. However, the people most likely to have successful careers in international business are those with fluency in both languages.