The correct answer to this open question is the following.
Although there are no options attached we can say the following.
Instead of internment camps, what the federal government can do to protect itself and its legal immigrant citizens during a war is to conscious them of the importance of being loyal to the United States government because now they live there and have to show respect, loyalty, appreciation, and love.
If that is not enough, the government could tell them that during times of war, these people are subjected to direct vigilance and the intervention of their communication devices, just to make sure they do not have any kind of misconduct, sending information that could compromise the security of the United States.
No more interim camps, as was the case of Manzanar, California, and many others during World War II.
Located in the state of California, Manzanar was a concentration camp ordered by US President Franklin D. Roosevelt during World War II, to send Japanese-American families that lived in the Pacific. From the end of 1942 to 1945, almost 118,000 people were sent to these camps. They lived under poor conditions due to the cold weather of the region and the dust storms.