Them practcing the war was a policy to end the us involvement in the vietnam war
Territory, the American's actually just purchased Alaska to help Russia out after the Crimean War, however, it gave them new territory in the Pacific region. At the time of the purchase, the public wasn't in support of it. However, later on, the purchase proved to be quite beneficial as Alaska proved to have oil reserves that the US can tap into.
The US before this point had an interest to stay neutral. However, in 1917, Jan 16, the US was informed by the British Empire US to join the war since Germany would help Mexico regain land lost, the US saw that as a problem. This incited them to declare war (This event was known as the Zimmerman Telegram)
So in summary, yes, it was in the national interest of the United States to declare war in 1917
The position that William Howard Taft wanted more than being the President of the United States was to be the C. Chief Justice of the Supreme Court. He fulfilled his dream and became the only president in history to serve as the Chief Justice of the Supreme Court.
