It has been said that invasion of foreign countries for regime change, such as Iraq, is morally justified. In light of recent unrest in Egypt and Libya, this issue is coming to the fore once again. In the example of Libya, the case is put forward that Gaddafi is committing humanitarian atrocities worthy of foreign military intervention. However, Gaddafi is not likely to give in easily. A Colonel, his military prowess and honour are clearly important to him. No doubt this would lead to a long, drawn out conflict involving the destruction of much of Libya's infrastructure, healthcare, education and social order. Many people would die, and an entire generation would be scarred by war. It may well lead to lasting damage to relations with Western countries, as well as accusations of whichever countries invaded behaving as a global bullies or imperialistic thugs. In short, the situation would have to be extremely, extremely bad and intervention would have to have a high chance of success for an invasion to be justified. The problem is, there are no examples where this has happened.
I am strongly of the opinion that countries need to arrive at Liberal Democracy through there own progress. Revolution from within has worked in many cases, such as France, but a foreign force imposing a system on an unwilling people never works. This will, no doubt, lead to accusations of moral relativism. However, I wouldn't say for one second that living in a monarchy or dictatorship is fine for other people, just that imposing democracy does not produce strong and stable government. At best a puppet regime of the invading nation(s) is installed, such as in Afghanistan and Iraq, and at worst a tyrant (Zimbabwe) or terrorist organisation (Palestine) is elected. And what happens then? The people have had their say, but it has led either directly or indirectly to a government we do not approve of and the problem is unresolved, despite all the above mentioned damages war does. Let us look at the most stable democracy in the world: the UK. The reason British Parliamentary Democracy has been so successful is that there have been hundreds of years of progress. Institutions can be changed over night, but minds take much longer to change. Many people 100 years ago thought the idea of women voting was preposterous, but now, as far as I know, pretty much no-one in the UK thinks women should not vote. If the UK had had votes for women imposed by a foreign power, the institution of voting would have been altered, but the minds of many Brits would not have been. It would have taken a long time to convince people, if the change was not reversed in the meantime. Instead, the emancipation of women came about organically and gradually within the UK, so everyone had time to get used to the idea, and the progress will (hopefully) last forever.
Another problem is who we invade. If we invade any countries that don't agree with our view of democracy we have a problem: there is no truly objective measure of the best and worst systems of government. The government of Iran, and much of the population, believe their theocracy is the best system, and is supported by a deity. If we believe we have the right to change governments we disagree with, it's hard to say that others do not also have this right. Saying that our system is so good we need to invade other countries to share it with them stinks of imperialism, and has caused many of the world's current problems.
I suppose my next argument is a kind of slippery slope. If we are prepared to invade one country for regime change, for example Zimbabwe, why not also invade China, North Korea, Iran, Saudi Arabia etc. And how bad do they need to be to require regime change? These examples have committed various human rights abuses, true, but so have the UK and USA, making it hard to hold the moral high ground. If it's a question of democracy, we also have a problem. British democracy is far from perfect. We still have more than half of the members of our legislature unelected. Again, it is difficult to hold the moral high ground, and would a more democratic nation, such as the USA or France be justified in invading the UK? We should try to perfect our own system of government before we impose it on others.
Some people would advocate foreign invasion only in examples of genocide, and this is certainly a much more persuasive argument. The most common example given by those who support so-called 'principled intervention' is World War Two. "Would you," they say, "not have intervened to stop the holocaust?" and certainly this is a difficult question to answer. Personally I am of the view that British involvement in World War Two was justified, but only for self-defensive reasons. If Hitler had not showed any interest in his neighbours' lands, Britain should not have become involved. The number of deaths within Germany from general repression was up to 3.2million, and the deaths from the holocaust were almost 6million. Shocking as these figures are, the number of military deaths as a result of the war was some 25million, including over 10million Soviet soldiers, and civilian deaths were as high as 50million worldwide. Furthermore, if Hitler had not invaded any other countries, fewer would have died as a result of his actions as many of the victims of his lunacy were Polish and Czech. This demonstrates how war often simply exacerbates the situation. In fact, the Nazi high command had not conceived of the 'final solution' until the war had started and they felt forced into finding a quick and extreme way of dealing with what they viewed as a problem. This is not to try and put the blame for what happened on anyone other than the Nazis, but war certainly did not help the matter.
The soul example I can think of where foreign military intervention may have been for the greater good is Rwanda, where the might of NATO forces would have met with relatively little resistance and the mass-extermination may have been stopped. However, there is still no certainty this would have been better overall as it could have caused many more deaths, and resulted in an equally unstable country. Essentially this line of thought is too hypothetical to pursue.
Wishing to avoid foreign military intervention can lead to accusations of 'not caring' or failing to act responsibly. However, I have explained why I believe that not intervening is almost always the best solution by all measures. There are also other ways to act, without resorting to violence. International pressure and sanctions can be effective, for example.
To sum up, I believe that as a general rule foreign military intervention for regime change should always be avoided, as it has never been successful and probably never will be.