The more precisely the position [of an electron] is determined, the less precisely the momentum is known, and conversely’.

This, as all clever Diplomat readers will know, is the classic formulation by Werner Heisenberg in 1927 of his famous ‘uncertainty principle’. By extension he argued that it was impossible to conduct an experiment on something without changing that very something in the process. A revolution in human thinking: objective scientific detachment was neither as objective nor as detached as we had supposed.

This same scientific philosophy can, of course,  be applied to the world of diplomacy. Especially when it comes to the complex issue of ‘interventions’ – moves by one state designed to impact directly on the affairs of another state, often without the formal consent of that state itself.

Interventions  make changes – that’s the point of them. But however clever and calculated an intervention, the changes it triggers immediately – and then in the years and decades to come – are necessarily unforeseeable and not always good. Politicians like the idea of showing voters results which are quick, predicted and positive. What if they instead get outcomes which are slow, unpredicted and negative?

Different Western governments are busy intervening around the world. The Iraq and Afghanistan conflicts linger. Although Iraq now has the prospect of standing on its own feet, where it decides to go is unclear. In Afghanistan’s, case we see a grim, ambiguous and increasingly unpopular war of attrition. The best result is an outcome which arguably delivers something in overall human rights gains (compared to the dismal state of what was there before the intervention started), but can be presented as having enough fleeting stability to allow the international forces to race for the exit and hope for the best.

The latest intervention to win formal UN blessing has been in Libya. On 21 March British Prime Minister David Cameron eloquently explained to Parliament the policy basis for the UK’s engagement. He identified three tests which had had to be met to justify military action: ‘Demonstrable need, regional support and a clear legal basis.’

After stressing that UN Security Council Resolution 1973 had provided the ‘full and unambiguous legal authority of the United Nations’ for the military action against the Gaddafi regime in Libya (and thereby defining clear water between this intervention and Tony Blair’s Iraq policy) the prime minister posed and answered some important questions:

• Has the use of force been reasonable?

• How is this in our national interest?

• Is this another Iraq?

• Will we be shouldering an unfair burden?

• Are the risks too great?

• Are we stirring up trouble?

These are all interesting questions and the prime minister gave direct answers to them. The statement reads well as a frank and confident presentation deserving parliamentary and public support – which it duly won.

The problem is that these are not the key questions. Here they are:

• Do we know what defines success for this intervention?

• Even if the intervention is needed, has regional support and is legal, will it in fact be done properly?

• What if – in the terms we ourselves define for success – it doesn’t work?

• Why are we intervening to stop the brutal Libyan regime killing freedom-loving Libyans, but not  the brutal Syrian (or Iranian) regime killing freedom-loving Syrians (or Iranians)?

• Where does the Israel–Palestine problem fit in?

•  All in all, is this policy wise?

The studied lack of clarity on these questions explains why almost within hours of the Western warplanes zooming off to attack Libyan tanks, unseemly disagreements were evident. Is the plan to topple or even kill Gaddafi? Or not? Who are these rebels anyway? Do the interveners want to win? Or is ‘winning’ an old-fashioned and politically incorrect idea these days? Is it a war? A conflict? Or a ‘kinetic military action’?

Hours slide into days; then weeks and months. As this piece is being written, the intervention in Libya is looking uncertain and unconvincing. Yes, the ability of the Libyan leadership to use heavy weaponry against the Libyan opposition and wider civilian population has been severely diminished – a core and just aim of the exercise. Hundreds, perhaps thousands, of lives have been saved. However, no cogent policy has emerged on what happens if Colonel Gaddafi does not politely resign.

An indefinite stalemate, maintained by sporadic NATO bombing missions if Gaddafi loyalists attack too hard and well? De facto partition along rough ‘tribal’ lines? A dirty deal between Gaddafi and assorted rebels which wins some respectable international support but leaves Libya sullenly much as it was before the violence started? Something else?

Meanwhile in nearby Syria and Yemen, the authorities are using deadly force to squash popular protests, unworried by any direct outside involvement intended to stop them. In Ivory Coast, French military forces (there under a UN mandate) have taken  take robust action in support of the opponents of President Gbagbo. In one fine episode of diplomatic excitement, Gbagbo loyalists seized the residence of Japanese ambassador Yoshifumi Okamura who retreated with some of his staff into a ‘safe room’ in his house. French troops swarmed to the rescue and set the ambassador free. Gbagbo may now have been toppled, but did French troops get a bit too involved in that outcome? If so, on what authority?   All in all, the whole intervention business is a conceptual and moral mess. When it comes to ‘protecting future generations’ from the supposed consequences of climate change prompted by human activity, the world tries quite hard to come up with shared active policies (especially if Western countries foot the bill). When it comes to protecting people now living from organised violence inflicted by their own leaders, it all gets very difficult (especially if Western countries foot the bill). Some causes are fashionable, others not.

Not all intervention involves armed force. Faced with a feeling that ‘something must be done’ to counter oppression in another country, international leaders first rummage in the bran tub of sanctions. The problem here is that generalised economic sanctions are slow to have an impact, and that impact is not felt by the regime concerned. Take Serbia, which suffered under numerous EU/US sanctions of different sorts for many years while Slobodan Milosevic was in power. Milosevic fell from power in 2000, but 11 years later the Serbian economy is in dismal shape – even under the most optimistic (and least realistic) growth scenarios, the negative impact of those sanctions on Serbia’s population will be felt for generations to come.

The current policy fad is to avoid such heavy structural damage and instead use targeted sanctions against named senior individuals, to stop key regime henchpersons benefiting from their misdeeds and encouraging those around them to break ranks. Do they work? Not really. In today’s globalised world, it’s hard to track money flashing to and fro between secret bank accounts held by close friends and relatives of those on the sanctions list. Look at Belarus President Alexander Lukashenko sailing serenely on, unmoved by different waves of EU measures intended to weaken him and empower pro-democracy organisations and politicians in the country.

If anything, the Gaddafi and Mubarak (and earlier Milosevic) case studies reinforce the worst instincts of the worst dictators: make clear from the start of any local unrest that you’ll do what it takes to stay in power. Under current management, Western governments may talk tough – but  that is negotiable. They may even blow up some of your loyalists if your methods are a bit too, ahem, blatant. But they are unlikely to come after you personally, as they’re squeamish – they have lawyers absurdly poring over their kinetic military actions to ensure that your human rights are not violated. Pshaw!

In other words, if you are a ‘bad leader’ and if (as is likely) your willingness to withstand pain and to dish out pain to your own local adversaries is greater than the international community’s willingness to inflict pain on you, hey presto – you can expect to stay in business indefinitely. Maybe too  a perverse reputation boost among the progressive global chattering classes for your heroic anti-imperialist defiance.

Let’s recall one intervention which worked. In 1983 US troops moved into tiny Grenada  and quickly toppled a self-proclaimed Marxist revolutionary clique which had murdered the island’s popular leader Maurice Bishop. This swift power-play by President Reagan was condemned by the UN General Assembly and hugely embarrassed British Prime Minister Margaret Thatcher (Grenada being a Commonwealth member). Yet it set Grenada back on a democratic path and was popular with the local population. Twenty-eight years later it looks like  a model example for using limited military force to achieve a just  and principled foreign policy objective.

Therefore what? Therefore nothing. Restoring constitutional government to an island with a population of just over 100,000 people is one thing. Sprawling Libya and its sprawling problems are quite another.