The European countries had been the birth place of Industrial revolution. But this had also created its ugly version called imperialism. In this the mother country would dominate the colony politically and economically for its own advantage. This was possible because of the absence of unity, prosperity in these countries.
Demand created by Industrial Revolution
The industrial revolution created a capitalist class that produced goods for earning profit. the main objective of production became earning as much profits as possible. For this the capitalists could reduce wages or increase production. But reduction of wages meant low purchasing power at home and increasing production would create more goods than demand. All European countries followed protectionist policies to prevent outsiders from selling to domestic market and protect home industry.
Hence there was a need to find markets outside Europe where goods could be sold. The Asian, African countries were such markets. The imperial nations set up factories there and slowly converted them to forts, finally the interfered in the country's politics to keep other imperial powers out. Finally the domestic industry was ruined and forced to become a consumer of European goods.
The other reason for colonialism was to protect interests and investments of the home country as a weak government in colonies would not be able to handle protests and the imperial nation's investments would be lost.
Industrial revolution in Europe needed raw materials to feed the industries. The domestic production wasn't enough to do this and so colonies were sought as they were suppliers of raw materials.
Improved roads, waterways and railways brought every country within the reach of industrialized nations. The raw materials could be transported easily and efficiently from Asian colonies to Europe. At the same time the finished goods to could be taken from Europe to colonies.
Communications like telegraph could be used to send messages to colonial governments and remote control the administration of the colonies.
Extreme Nationalism
Colonies became a source of pride and status. Writers and leaders of countries began to raise slogans that more colonies should be brought under control to increase the nation's prestige. The colonies were annexed and later more were acquired to protect the existing colonies e.g. England captured South Africa to protect its trade routes to India.
Colonies also increased the man power of imperialists as the people from colonies could be recruited forcibly into the armies of the nations.
Civilizing Mission
The imperialists believed that it was the White mans burden to civilize the inferior people and convert them to Christianity. The missionaries would often go alone into unknown areas and spread the religion in those places. But the missionaries were also followed by traders who looked for opportunities and soldiers sent to protect the missionaries.
Explorers and Adventurers
The explorers who travel to many regions and bring back reports on the usefulness of these regions to trade with the home country. The home country would then establish a trading post and soon in pretext of protecting the trading interest colonize the entire region.
Conditions that favored Imperialism in Asia and Africa
The lack of modern nationalism in such areas meant that people often owed allegiance to princes and tribal leaders. The leaders were divided and the Europeans took advantage of this. The Europeans were superior in military tactics too. The Asian artisan's were skilled but their techniques were old and only a small number could be produced.
The machine manufactured goods were easily dominant over these.
China was a producer of tea, silk and other goods but there was no market for British goods in China. Also China had a restricted trade policy and a handful of ports were open for foreign trade. The British had to pay gold and silver for trade and so were having a negative balance of trade. Hence they started cultivating opium in India and sold it to Chinese smugglers who paid them in Gold. This was used to pay for Chinese imports. This system was favorable to British but damaged Chinese morally.
The Chinese government destroyed the opium cargo and England attacked it. In the war the Chinese were easily defeated. They had to open ports for foreign trade. Island of Hong Kong was handed over to British. However this didn't end here and a second war was fought that resulted in more ports opening and granting of extra territorial rights to Foreign powers i.e. no foreign citizen would be tried in Chinese courts for crimes in China. China also couldn't impose tariff on foreign made goods.
China had a war with Japan that was trying to increase its influence in the Asian region. It wanted Korea which was strategically located and had vast natural resources.China lost in the War and had to pay war damages to Japan and surrender the island of Formosa. With the pretext of helping China financially the imperial powers like England, France, Germany, Russia gave loans to it in return for privileges of trade.
Sphere of influences were created by these nations. In them the imperial power had the sole right to build transport, communication lines and trade. This was called "Cutting of the Chinese Melon".
The United States was facing a threat to its
trade with China and so came up with the "Open Door Policy" which
meant that any country could trade anywhere in China. This
benefited US, England too agreed to this as it feared that Russia
or Japan could easily capture China.
Boxer Rebellion occurred in China due to the Chinese community being fed up with corruption in Chinese government, interference of christian missionaries and increasing foreign interference. But this rebellion was easily crushed and led to more damages on China.
Thus though China wasn't dominated like India by a single foreign power it too had become like a colony.
Japan too was like any other Asian country. Commodore Perry of USA forced it to open its ports to foreign trade. Similar agreements were made with other European nations. But Japan didn't end like other Asian colonies. This was due to the Meiji Restoration.
Under Emperor Meiji the following reforms were carried out in Japan. Universalize education, building transport and communication facilities, building ports and army, incentivize industry and trade. All this made her into a Industrial power but at the same time elements of imperialism too developed there.
The Island of Japan wasn't with natural resources and so Japan eyed the Korean pennsula and China. After a brief war with China which it won due to adoption of modern military tactics, Korea and Formosa were ceded to it. Japan also controlled trade and territory in China. Russian - Japan was led to defeat of Russia and capture of Sakhalin from it.
European nations had begun exploration of African nations during the beginning of 15th century but this was confined mostly to the exterior or coastal regions. Even this contact was disastrous for Africans as Slave Trade emerged.
The Spanish and Portuguese had captured Central and Latin America and exterminated the local populations. There was a demand for slaves in such regions. Hence Portuguese captured slaves from Africa took them to the slave market in Lisbon and sold for commodities or firearms. The slaves were taken to Latin America and sold to plantations.
The African chiefs participated in this trade for purchasing firearms of Europeans. However this trade had disastrous consequences for Africans. Every month 5000 were transported to American plantations and half of them died en-route. The Slave trade also created a technologically backward Africa to this day.
By the 19th century trade in slaves had lost its importance and had led to start of a second type of exploitation - Colonies. The interior regions were explored and war on tribal chiefs were made. The Africans were easily conquered as they lacked unity and arms to match the Europeans.
United States had gained freedom in 1793 and it had increased its territory by was on Mexico. The purchase of Florida, Alaska and Louisiana had increased its territory. The short civil war ended slavery and after 1865 industrialization too increased and made USA a dominant force in the western hemisphere.
It built the third largest navy and asserted its right to influence and interfere in the affairs of its neighbors if its trade and investment interests were compromised. The Gunboat diplomacy by Commodore Perry had opened Japan for trade and Open door policy over china to benefited it.
Just like Europe and Japan imperialist elements developed in USA that wanted it to be a leader in the race for colonies. The leaders of USA also wanted it to participate in the civilizing mission of uplifting the backward areas of Asia.
The US declared that only it could intervene in the affairs of its neighbors and cautioned the Europeans from intervening in the Western hemisphere. It sent its troops if it felt that the events in Central or Latin American countries were against its investment. It also followed a policy of using investments in these regions as an excuse to dominate them.
This "Big Stick" or "Dollar Diplomacy" of USA was reason for its increasing influence in South America. The countries of South though had political freedom but were ruled by Corrupt warlords who sold land and exploitation concessions to foreign powers for money. The trading companies of USA invested in such countries and successfully dominated them economically.
The Imperialism and its effect of colonization damaged the non industrial world and led to its economic subjugation to the West. The worst effects are seen in Africa that has remained backward to this day.
Trade and industry of these colonies was destroyed and hasn't recovered its glorious heights of the past even today e.g. China and India.
The one sided trade policy of making the colonies a source of raw material and consumer of finished goods had led them to remain one crop economies and entirely dependent on Europe for its basic needs. Natural calamities created destruction in these nations even today.