They would offer them power and riches if they agreed to join peacefully.
The die is cast means an event has happened or a decision has been taken that cannot be changed. It is also a variation of a Latin phrase attributed by Suetonius to Julius Caesar on January 10, 49 BC, as he led his army across the Rubicon river in Northern Italy.
Today, the phrase crossing the Rubicon is an idiom that means to pass a point of no return.
Thee native americans :) PM me for any further questions!