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 duration of the memory is limited, but also the amount of information that can be stored (and successfully recalled). Humans can store about seven numbers, six letters or five short words in short term memory at any one time. Memory for words depends on the length of the words and curiously, the amount of time required to say the word out loud is more important than the number of letters in the word.