We (via the ICANN, see below) actually have the power to do that. The .af TLD only works because the root DNS servers delegate the .af TLD to the Afghan nameservers. As soon as we stop doing that, they are powerless.
And as a bonus, the ICANN could set the nameservers to OpenNIC's, setting a precedent for a more public ownership of the Internet. But somehow I highly doubt they would ever do that...
Edit: I did what I documented here to do, and here is the (automated) answer from the ICANN:
Dear [name],
Thank you for contacting ICANN Contractual Compliance.
Your complaint involved a domain name registered under a country code top-level domain.
Please note that ICANN has no contractual authority to address complaints involving country code top-level domains (ccTLDs), such as .us, .eu, .ac, or domain names registered under a ccTLD (e.g. example.us, example.eu, example.ac). ICANN does not accredit registrars or set policy for ccTLDs and has no contractual authority to take compliance action against ccTLD operators. For inquiries and issues involving ccTLDs, you may wish to contact the relevant ccTLD manager using the contact details at https://www.iana.org/domains/root/db. This page will also help you determine which top-level domains (TLDs) are country codes (outside of ICANNs scope) and which ones are generic (within ICANNs scope).
Please note that responses to closed cases are not monitored. Therefore, if you require future assistance or have any questions regarding this case that is being closed, please email compliance@icann.org. if you have a new complaint, please submit it at http://www.icann.org/resources/compliance/complaints.
ICANN is requesting your feedback on this closed complaint. Please complete this optional survey here.