Why won't a Stealth Bomber fire on cities anymore?

My stealth bomber won't fire on an enemy. It fired in the previous turn and now it won't attack my enemy's city. Does anyone have any ideas as to why this is?


Solution 1:

Perhaps you have lost sight of the enemy city (is it greyed out)? Units can only attack other units / cities if you currently have them in sight. A Stealth Bomber has a huge range but it has to have some other unit(s) providing sight to the intended target.