By June 2004, it was confirmed that the US was using torture at secret detention sites and at Guantánamo Bay, Cuba. It was in that month that piles of "torture memos" were released to the public. Torture did not officially end until President Obama took office in January 2009.

A similar story is emerging with respect to targeted killing. The Obama administration has produced its own infamous memo; like many of the torture memos, it was written by lawyers in the Department of Justice's Office of Legal Counsel. It concerns something that many consider worse than torture: the memo apparently seeks to justify "targeted killing".

Calls have gone out for the release of the memo, but there really is no need. We did need to see the torture memos, but not because anyone with legal expertise on the subject would be enlightened by the analysis – torture is absolutely prohibited. The legal analysis could only be specious. Rather, prior to mid 2004, the use of torture, rendition and secret detention were only rumored. The fact of the memos gave credence to speculation.

In the case of targeted killing, the world can see what is happening. The memo need not be published to confirm the fact. And, as with torture, the memo will not contain a persuasive legal argument respecting the fundamental human rights and humanitarian law at issue.

"Targeted killing" is the killing of certain individuals away from battle zones using military means, including missiles, bombs and commando raids. The missiles and bombs are often delivered by drone aircraft. Given the munitions, it is the rare attack that spares the lives of bystanders – over 2,200 persons are estimated to have been killed in the three years of the Obama administration in Pakistan alone. We have no estimates for deaths in Yemen or Somalia, the other scenes of relentless attacks.

"Targeted killing" has become the euphemism du jour. Remember "harsh interrogation"? The conduct discussed in the killing memo was once simply referred to as assassination.

More and more people are pushing back against the policy. They are reacting, no doubt, to the fact that President Obama has authorized many times the killings that President Bush did. Obama apparently authorized the killing of an American in Yemen, and he is now engaged in the building of drone bases to continue the campaign of assassination. Greg Miller of the Washington Post notes that "no president has ever relied so extensively on the secret killing of individuals to advance the nation's security goals."

In 2001, the US ambassador to Israel, Martin Indyk, stated on Israeli television in connection with Israeli targeted killing of suspected terrorists:

"The United States government is very clearly on the record as against targeted assassinations. They are extrajudicial killings, and we do not support that."

The US did not support such killing for fundamental reasons of law and morality. Fundamental principles of law protect the human right to life and due process of law. Unlike torture, which is never permitted, states are permitted to allow designated authorities to carry out the use of lethal force in certain limited situations. In situations of armed conflict hostilities, lawful combatants will not be prosecuted for killing that complies with international humanitarian law. Today, under the international legal definition of armed conflict, the United States is involved in such hostilities in one country only: Afghanistan.

Beyond Afghanistan, any use of lethal force by designated authorities of the United States must follow the normal human rights limits on peacetime resort to lethal force. Authorities may engage in lethal force when necessary to save a human life immediately, if there is no alternative. In other cases, an attempt to arrest is required, followed by a fair trial within a reasonable period.

These restrictive international legal rules on killing are derived from moral principle, just as the rules against torture are. Torture and targeted killing have more in common, however. Neither is an effective means toward the ends sought by those who employ them: torture is an unreliable means of information gathering; targeted killing is ineffective on dealing with the challenge of non-state actor terrorist or militant groups.

But even if there was any data at all about assassination having a long-term positive impact on suppressing terrorism – which there is not – the data would not change the law and morality against it. Indeed, the president criticized the assassination of a nuclear scientist in Tehran. Drone attacks outside of armed conflict zones are committing the same wrong – though usually more bystanders are killed than was the case in Iran.

President Barack Obama's 3 January 2011 letter introducing his national security strategy for the coming decade states that America's overriding goals are "security", "prosperity" and a "just and sustainable international order where the rights and responsibilities of nations and peoples are upheld, especially the fundamental rights of every human being." Impressive, even inspiring – but for the fact that the president's campaign of assassination is denying many hundreds of individuals their right to life. The security strategy looks set to dramatically ramp up the number and deployment of attack drones from new permanent bases around the world.

Neither torture nor targeted killing will accomplish the goal of a "just and sustainable international order where the rights and responsibilities of nations and peoples are upheld". Human rights advocates, legal scholars, religious leaders, occupiers and voters are again pushing back against a practice carried out in our names that must end.