Over the last century, international sanctions have become a geopolitical weapon of choice. At interstate level they have had mixed results. The 1940 US-led oil embargo on Japan in the face of its continued aggression in China and Indochina finally convinced Tokyo to attack the United States and Great Britain.

More recently, sanctions on apartheid South Africa made a significant but not overwhelming contribution to the end of white rule. Sanctions on Saddam Hussein’s Iraq arguably did succeed in that they caused him to abandon his WMD program. However, the George W. Bush White House deliberately ignored the finding of UN inspectors that they had indeed gone. In the end the sanctions on Iraq only hurt ordinary citizens, as top members of the regime could look after themselves.

The Iranian elite likewise managed to featherbed themselves and their praetorian Revolutionary Guards against the worst effects of the international sanctions that President Obama so wantonly threw away with his pathetic 2015 nuclear agreement. But the reason the ayatollahs were forced to the negotiating table was not through a lack of their own creature comforts but the collapse of their country’s economy. Popular unrest was approaching a level where the regime’s very existence was in doubt. Today, economic sanctions against Russia still remain more a serious inconvenience to the Kremlin than a tool with which to lever it to change what Washington views as its confrontational policies.

But there is another level of international sanctions, those that are applied to individuals who are alleged to have violated human rights or been responsible for other major crimes. Thus at the moment, key members of the inner circle of Russian President Vladimir Putin, as well as top Syrians, Iranians and North Koreans, are subject to financial restrictions and travel bans. If they step outside of their country, some of them are likely to be arrested under international warrants that are currently sealed.

The problem with these measures aimed at named parties is that they are easily put in place by political leaders who want desperately to be seen to be “doing something” in the face of egregious crimes that shock their voters back home. If individual sanctions are to succeed they need to be consistent and also enforceable.

The United Nations has just provided an object lesson in how not to apply them. The Security Council this week agreed to sanction Salah Badi, the hardline leader of a Libyan Muslim Brotherhood militia who, among many acts of wanton destruction, is accused of leading recent murderous fighting in the capital Tripoli. As far as is known. Badi has no international assets which can be frozen and only travels to MB-supporting Turkey which will never detain him.

Libyans across a normally deeply-divided political spectrum are dismayed at this UN action, not because they disagree with it but because they think other militia leaders ought also to have been sanctioned, including the thuggish Mohammed Al-Kani and his brothers who actually began the Tripoli fighting in which Badi later joined.

Singling out this one individual has caused widespread local dismay and has further undermined the already-tarnished reputation of the local UN body, UNSMIL. There is substantial evidence against most of the murderous militia leaders in Libya. The UN needs to sanction absolutely all of them, otherwise its proscriptions are utterly meaningless.