What "momentous decision" was made by Robert Frost in 1912?

Though Robert Frost is known as one of America's great poets, he first gained momentum as a publishing poet while he was living in Great Britain with this family. 1912 was the year in which Frost decided to leave his farm life in New Hampshire. He decided to sell the farm partially because he and his wife, Elinor, had proved to be unsuccessful farmers, but the farm also held memories of some of his children dying. So though Frost had become acclimated to living in a rural setting, he moved his family to Europe.
Frost found success there, having great names like Ezra Pound positively review his writing. But as the tensions grew in the continent and the conflict that was later to be known as World War I began, Frost decided to return to the United States. By 1916, Frost had joined forces with an editor who would help to propel his career, and many of the poems that helped him to launch his career back in America were written during his time in the UK.
https://www.biography.com/writer/robert-frost