I have been reading Max Hastings' great work, Catastrophe, about the outbreak of World War 1, and looking at the leadership reasons for bringing their countries to a war footing.
In each case, fear of invasion by the Russians has been the driving force: in 1914 the German Kaiser wanted to pre-empt Russian military growth and check their military strength before they got too strong for German forces to rebuff on the Eastern front. The unexpected murders of the Arch Duke Ferdinand and his wife provided an opportunity for Germany & Russia to square up against each other with Serbia as the excuse.
In 1962 Cuba became the equivalent Serbian pinchpoint, and now in 2014 it seems that the Crimean Peninsula - known to us all by name thanks to its 19th century war, but probably hard for most people to pinpoint on a map until a fortnight ago - has become the focus of the present day crisis.
Should we be anxious? Have all the world's leaders got nerves of steel & do they actually want to do the right thing? Is Putin actually bothered about maintaining stability, or is he driven by a longstanding desire to see Russian territory return to USSR size?
News this morning is that Russian money in the western markets is being pulled out fast, for fear of sanctions & blockage. Might it be the case that the oligarchs' vast personal fortunes - including Putin's - may be the key to stability? That childhood phrase which my Mum's hippy musician friends used to disparaging sing about.... That "money makes the world go round", may prove key to the aversion of military aggression in Crimea.