First, preemptive and preventive uses of force are often justified by claiming either that there is substantial risk of a future attack or that it is difficult to ascertain how dangerous the target is.
Short-Term Memory: Up to 7 Items, But Highly Volatile. Many psychology experiments have shown that our short-term memory can hold only a limited number of separate items. The average is about 7 items, plus or minus 2, depending on the individual. You can easily confirm this by reading someone a series of words that have no connection with one another, then asking this person to repeat them.
The short-term memory has a limited capacity, which can be readily illustrated by the simple expedient of trying to remember a list of random items (without allowing repetition or reinforcement) and seeing when errors begin to creep in.