It will kill people. People live in Mecca.
Like I said earlier, Truman knew this. It’s not hard to figure out. So take some advice from an idiot and review your history.
Only a few. The city is highly populous. However, he’s obviously talking about using a tactical nuclear weapon to take out the shrine. In order to take out the city, you would need a strategic nuclear weapon. This, however, is moot. In case we’ve all forgotten, Mecca is in Saudi Arabia, a US ally.