The conduct of our government heavily influences the practices of other countries. The United States would in all likelihood not endorse the authority it claims for targeted killings if it were asserted by other countries. Americans would surely be appalled if another country claimed the right to send a drone after a declared enemy in Wyoming.
The government has the tools it needs to address the threat posed by suspected terrorists, including Americans, who find refuge in other countries. It can indict suspected terrorists and seek their extradition. It can seize their assets. It can share intelligence with other countries so that they can charge and try suspected terrorists. It can provide financial and technical support to other countries’ law enforcement and intelligence services. In a truly extraordinary case, the government may have no choice but to use lethal force to address a threat that is both grave and imminent. But if we are to preserve anything resembling the rule of law, the government’s authority to use lethal force against its own citizens must be limited to such grave and imminent threats.