National Security: the colonized island country has deepwater ports for refueling the mother country's navy and merchant marine. it also has an airfield. Is imperialism in this case justified, sometimes justified, or never justified and why.

Imperialism is never justified.

Explanation:

In the question above we see that there is a country that has deep water ports and an airfield. These two factors are elements that generate wealth for that country and that belongs to the national territory. In this case, it is not justified that another country, out of greed, uses its influence and strength to dominate these elements through imperialism, exploiting foreign wealth for its own growth, while the country that owns that wealth is devalued.

the constitution of the united states gave congress the absolute authority over immigration laws

a historian researching the immigration policies of the early 1900s would expect a source written today,rather than in 1910 to :

( a ) be more interested in objective data and statistics.