With the arrival of one infected individual, two nurses that attempted to treat the doomed man now have Ebola here in the United States. As such, Ebola is a clear and present danger to the United States of America.
The people & governments of West Africa have chosen not to modify their culture with modern medical knowledge to ensure public health and safety and stem the infection. They struck at Ebola clinics, further spreading the disease.
This has been and is done even though the truth has been presented to the people of these poor nations.
These can be considered biological attacks on the world as a whole, including this great nation.
As such, we are legally justified in responding to said attacks, using weapons of mass destruction, to effectively eliminate the threat at the source.