Answer:
The sentence in the excerpt that suggests that the US government would gain more power to prepare for war is New circumstances are constantly begetting new needs for our safety.
Step-by-step explanation:
This sentence suggests that the United States government would become more powerful if they prepare for war because it makes the claim that new circumstances bring about new needs for safety and adequate preparation helps the country not to be caught unawares.
The impassioned appeal by Theodore Roosevelt was to enable Congress approve new appropriations and authorizations to finish off what they have begun.