When you study the history of Indonesia to try and predict which nation contemporary Indonesians would see as their natural rivals on the Football field, there are 3 clear candidates.
The first would be the Netherlands. The Dutch were the foreign nation that had the longest presence in the Indonesian archipelago, being the colonists of what we now call Indonesia. Dutch presence can be divided into two parts; the period of VOC (Dutch East India Company) interaction with natives for about 200 years and the period afterward in which the Dutch Crown itself assumed administrative control over the archipelago for 149 years. To Indonesians at the time however the two periods would have felt similar, if not identical. The Dutch were tough rulers, exploiting the abundant commodities of the islands and violently suppressing dissent.
Dutch colonialism fueled an Indonesian nationalism that had not previously existed across ethnically and culturally diverse islands, paving the way for the independence movement. The fight for Indonesian independence was long and costly as natives successfully fought off the Japanese and then the Dutch in the 1940s before declaring independence in 1949. Centuries of harsh Dutch colonialism left a bitter taste in the mouth of Indonesians in the 20th century, but the younger generations today actually have far less beef with the Dutch, meaning that they don’t really view the Netherlands as a sporting rival.
The second nomination would be Japan. Through the late 19th and early 20th centuries Japan saw a wave of nationalism similar to that seen across the industrialising European nation states of the era. The China’s loss and subsequent economic subjugation to Great Britain in the Opium Wars sent shock waves through traditional, conservative Japanese society. The Japanese began to fear for their own safety as individuals, but also increasingly as a collective, as a nation. Japanese society underwent comprehensive restructuring and modernised quickly, importing European technology to revamp the armed forces in order to be capable of defending Japan against foreign threat.
But rising Japanese nationalism led to colonial ambitions of their own. While WWII broke out in Europe, Japanese forces invaded and occupied several parts of East and South East Asia, including what we now call Indonesia. The lighting-fast success of the Japanese in taking land from the European colonists demonstrated to fellow Asians previously under colonial rule that European “culturally superiority” was a sham, as well as garnering support for the Japanese cause (in some areas) at least at the beginning. But the violence experienced at the hands of the Japanese in this era was so extensive that it affects Japanese relationships with many Asian nations to this day. Many modern Indonesians feel anger toward Japan as a result of this period. But Japan is still not considered the main sporting rival of Indonesia.
The third nomination is Timor Leste, a.k.a. East Timor. The island of Timor sits within the Indonesian archipelago, North of Australia and West of large Papua, and has been home to a predominantly Catholic population for the past 400 hundred years. Timorese culture and identity are product of the Portuguese presence in the region. The Portuguese were the first European nation in the post-Colombian era who made meaningful contact with South East Asia, most notably in Melaka and Jakarta. Many of the Portuguese or descendants of the Portuguese came to inhabit Timor over time, bringing their language and religion to the island. While the rest of Indonesia remained largely Islamic, Timor is now predominantly Catholic. Culturally separate from the rest of Indonesia, Timor Leste seceded from Indonesia in 2004, not without controversy.
Many patriotic Indonesians still feel that Timor Leste belongs to Indonesia. The mixture of frustration and anger manifests itself at sporting events when Indonesia plays against Timor Leste. But being such a small country with a small population, Indonesians don’t consider Timor Leste to be their main sporting rival on a national level, though they continue to hold grudges against the young nation.
Not the Netherlands. Not Japan. Not Timor Leste. Indonesia’s biggest sporting rival is undoubtedly Malaysia.