The Treaty of 1818 was signed with the United States and Great Britain. The land that was the British Cession, which consisted of parts of the Dakotas and Minnesota. The Oregon Territory was achieved by the United States in 1846 which was also from Great Britain.
The reliance could be seen on how we acquire our military draft.
For example, countries such as Russia and south Korea implemented a mandatory military services for all adult men. (they're require to served at the military for around 1-2 years).
United states on the other hand, does not implement such mandatory military draft. All of our forces were acquired through voluntary methods without government force.
Since the nature of war has changed, voluntary method is more than enough since war that conducted on modern time would most likely relied on mass destruction weapons or advanced vehicles.
Khmer Rouge is associated with Cambodia.
The monarchy undertakes constitutional and representational duties
