While the Kandrian Empire thanked Founding Emperor Ra for building the Kandrian Empire on the coasts of the Panama Continent, furthest away from the Beast Domain, most of human civilization was not as fortunate as the Kandrians were.
Many of them didn't have the time to gather intelligence or prepare their troops well in advance.
The simple fact of the matter was that most nations simply weren't in a state to respond to such a crisis abruptly.
For instance, it was rarely the case that most of a nation's Martial Artists were within the border of the nation. In most cases, anywhere between thirty to fifty percent of a nation's Martial Artists were outside of the nation, either on state missions on commission or any other operation.
In the case of the East Panamic Treaty Alliance, it was the war.
Human civilization desperately scrambled to get all its Martial Artists back home before the Beast Incursion reached their borders.