The definition of preemptive is  something done in anticipation of another action or done to prevent something from happening. When the military takes action against forces they believe intend to do harm to them, this is an example of a preemptive strike.
Newsfront. Just 1 percent of illegal immigrants living in the United States last year were deported-a dramatic 25 percent drop from the previous year-a change the Obama Administration says is on purpose due to a shift in focus. illegal,immigrants,deported,drop. 400.
That year, there were 2.2 million immigrants in the United States, nearly 10 percent of the total population. Between 1860 and 1920, the immigrant share of the total population fluctuated between 13 and nearly 15 percent, peaking at 14.8 percent in 1890, mainly due to high levels of European immigration.