During the Aceh War the Acehnese klewang proved very effective in close quarters combat against the sabre-wielding Dutch troops and the Royal Netherlands East Indies Army.
Mobile troops armed with carbines and klewang succeeded in suppressing Aceh resistance where traditional infantry with rifle and bayonet had failed.
The Dutch klewang was developed at the end of the 19th century, because firearms and also traditional swords were not always reliable at that time, especially in the jungle.
These military versions were shortened sabres completely by European design, and better suited for close quarter fighting and jungle warfare.
Even from the time after Aceh was pacified by the Dutch to the 1930s and right through World War II, lone wolf Acehnese without generals would still attack Europeans in hopes of getting martyred themselves and attaining paradise.