That is a good point.
Koran 9.5-6, So when the sacred months have passed away, then slay the idolaters wherever you find them, and take them captives and besiege them and lie in wait for them in every ambush, then if they repent and keep up prayer and pay the poor-rate, leave their way free to them; surely Allah is Forgiving, Merciful. (9.6) And if one of the idolaters seek protection from you, grant him protection till he hears the word of Allah, then make him attain his place of safety; this is because they are a people who do not know.