What are acceptable reasons for the United States to become involved in a foreign war? (the spanish american war)

image result for what are some causes and effects of pontiac's rebellion?

the colonists were also expected to pay a tax to meet the costs of establishing and manning the borders of the proclamation line which led to the belief that the king had sided with the indians despite pontiac's rebellion, against the interests of the settlers. this contributed to the causes of the american revolution.