By the way... to respond to the original post, the attacks don't stop, and tanks are invulnerable. There aren't any anti-tank weapons in the game -- just swords and small arms. Once there's a way to purchase smuggled weapons at black market premiums, it will become possible to add RPGs or something, but I'd have to put a lot of thought into the way the game world would respond to the LCS using rockets to blow up tanks before doing that.
Additionally, at the moment the game eschews explosives entirely, which gives it a very distinctive feel -- bombs are generally the weapon of choice for undermanned insurgent political campaigns/terrorists, since they give a lot of bang for your manpower. Realistically, an LCS group wouldn't shoot up the police headquarters, they'd figure out a way to bomb it, causing maximum collateral damage. But I'm not sure that's the game we're going for.
One of my goals is to make raids less common early on and more serious later on. They're already crippling for many groups, but if you can fight them off at the highest level, you're pretty much set for the game, and they're just a repeated irritation. One thing they should do is lay siege to your compound regardless of whether you fortified for it, and just bomb it repeatedly. They already bomb the compound during sieges, but right now, they don't always lay siege, and you can just fight right away. Then, when you attempt to escape/engage, they can sit outside the compound with their tanks and just try to shell anything that comes out the door.
Other things needed for raids include negotiators for sieges, and some kind of way to lift the siege from the outside -- whether by something like bringing in a force of gangsters to attack the police station, or just attacking the sieging force itself.
One thing that would be interesting is if buildings that get shelled by tanks or rocketed by aerial units would be devastated and unable to function as safehouses in the future. When things are calm and the economy is good these could be cleaned up and repaired over time. This could go hand in hand with the ability to knock certain buildings off-line with a strong attack, like attacking a sweatshop and doing so much damage that they have to close down, which is another feature I'd like to see. Abandoned factory safehouses could be reclaimed by corporations that buy the property (perhaps sending inspectors first, who would stumble across any safehouse there), while attacks on certain buildings could cause them to become abandoned, and eventually be available for making into a safehouse. But crushing local businesses that employ people could make the LCS become very unpopular with the general public. Lots of possibilities here.