If your Country bans Bitcoin, transfer your Bitcoin to a wallet of a foreign country (Coinbase operates in 32 countries). If you want to cash in, then use third party services like Virwox to get USD in Paypal, then use Paypal to get cash in your local currency.
Bitcoin is like Torrent, peer to peer and you cant block it. If you have access to internet, You can use Bitcoin anytime, anywhere!
I'm not sure if coinbase is exactly the company you can rely on if your country bans bitcoin, as they will very likely report to the local authorities sooner or later. But there are other options, such as decentralized exchanges.