1. A larger market base simply equates to potentially more capital and larger profits. And the same can be said about importing products from China; A cheaper manufacturing base simply equates to potentially more capital and larger profits. A billion plus consumers that are hungry for imported Western products also Western consumers hungry for inexpensive exported products from China.
2. The desire for gold influenced European decision making during the Scramble for Africa by gold producing areas more sought after. The countries that could not claim the interior gold producing regions made sure they got the exterior port regions.
3. International trade enables specialization, which brings increased efficiency and greater competition to spur the market
4.
Economic - motives included the desire to make money, to expand and control foreign trade, to create new markets for products, to acquire raw materials and cheap labor, to compete for investments and resources, and to export industrial technology and transportation methods. Political- motives were based on a nation's desire to gain power, to compete with other European countries, to expand territory, to exercise military force, to gain prestige by winning colonies, and to boost national pride and security.
For Asia it bought modernization, for Africa it bought degeneration of its population and resources, for Latin America it destroyed their culture but bought a new one which was destined for greatness but somehow failed, for north America it destroyed their old culture and bought a new one destined to fail but somehow succeeded, and for Europe it just strengthened them for a few extra 100 years.