Iraq, Afghanistan and Libya are all different as we and the US went into these countries to try and improve them and then left. Crimea is a land grab and is against the UN charter that most countries have signed up to. Now if we are going to go back to a pre-1950's system, all countries are going to have to spend substantially more on defense budgets and we can all expect to lose loved ones in the subsequent wars.
I too, can understand why Putin has grabbed Crimea to protect his Black Sea Fleet base, but that does not make it right. To say it is nothing to do with us is wrong as bullying land grabbing dictators, tend to get a taste for this and like the popularity that they enjoy as a result.
In 1914 we could have done much more to influence the Austra, Germany, Serbia, Russia situation that started WWI, not getting involved at that point worked well for us, not. Putin with his opportunistic land grabs reminds me very much of Hitler in the 1930's, where our appeasement and Munich agreement also worked well for us, not.
Sanctions are a very weak response, but the best we have in the circumstances where we don't want to risk a direct US- Russia conflict. No response means it is a no lose game for Putin he will gobble up the rest of the Ukraine and then start on the Baltic states. then you have real decisions to make as they are part of Nato. If they don't respond, they are then a busted flush, if you do you may well have started an avoidable WWIII. As Putin yearns to recreate the old Soviet empire, take your pick on who is next probably, Belarus, Moldova and all of the bordering -stans, after this comes Poland, Hungary, Czech Republic, Eastern Germany, The Balkans etc etc. The world since the seizing of Abkhazia, South Ossetia and now Crimea has become a much more dangerous place.
If the west is seen to do nothing, then China might as well join the game and seize all the islands and sea areas that they are in dispute in with all of their neighbours, after all it is nothing to do with us. Let Iran become a nuclear power, after all it is nothing to do with us, until we all suffer from a nuclear winter and the radioactive fallout.
Churchill had a go saying about appeasers. They feed everybody else to the crocodiles, hoping it will eat them last.
Personally I look at sanctions as a bit like giving to charities, we know doing so makes us a bit poorer, but we do so in the hope of making the world and other peoples lives a bit better.
Obuma like Carter is a dove and without any world leadership, the world gets a whole lot more dangerous, where gangsters, despots and chancers try their hand, expecting to get away with it. Like it or not in the 18th and 19th centuries we were the worlds policeman. After WWI / WWII we passed that baton on to the US and as the world's only superpower they have global responsibilities.
Putins weakness is his economy, petro dollars are being used to make him and his close circle of oligarchs very rich at the expense of modernising the economy and as one US senator said the other day "It is a gas station with a country attached to it". Growth has gone from 5.5% to an average of 1.3% over the last 3 years and as the US tapers its QE, it is causing problems in Russia along with other developing countries. So far his Crimea adventure has cost the country over $70bn in propping up the Ruble, raising interest rates from 5.5% to 7% and a 9% drop on their stock market. Weak response although it is sanctions are the only weapon we currently have in the cupboard.
If Russia does invade Ukraine, then it will be another Afghanistan, the Ukrainians will fight, they are the famous Partisans of WWII and many were in the Red Army in Soviet times and were on the wrong end of the irregular forces there. I don't think Europe needs another Balkans style war.