Concerning the 'tense' atmosphere, here is an excerpt from Niall Ferguson's Ascent of Money, where he argues that prevailing pre-war opinion about practical impossibility of great war in a world with intertwined economic interests is similar to today's view that war between let's say USA and China is impossible:
"To many businessmen - from Ivan Bloch in Tsarist Russia to Andrew
Carnegie in the United States - it was self-evident that a major
war would be catastrophic for the capitalist system. In 1898
Bloch published a massive six-volume work entitled The Future
of War which argued that, because of technological advances in
the destructiveness of weaponry, war essentially had no future.
Any attempt to wage it on a large scale would end in 'the bankruptcy
of nations'. In 1 9 1 0 , the same year that Carnegie established
his Endowment for International Peace, the left-leaning
British journalist Norman Angell published The Great Illusion,
in which he argued that a war between the great powers had
become an economic impossibility precisely because of 'the delicate
interdependence of our credit-built finance'. In the spring
of 1 9 1 4 an international commission published its report into the
outrages committed during the Balkan Wars of 1 9 1 2 - 1 3 . Despite
the evidence he and his colleagues confronted of wars waged à
l'outrance between entire populations, the commission's chairman
noted in his introduction that the great powers of Europe
(unlike the petty Balkan states) 'had discovered the obvious truth
that the richest country has the most to lose by war, and each
country wishes for peace above all things'. One of the British
members of the commission, Henry Noel Brailsford - a staunch
supporter of the Independent Labour Party and author of a fierce
critique of the arms industry (The War of Steel and Gold) -
declared:
In Europe the epoch of conquest is over and save in the Balkans and
perhaps on the fringes of the Austrian and Russian empires, it is as
certain as anything in politics that the frontiers of our national states
are finally drawn. My own belief is that there will be no more wars
among the six great powers.
Financial markets had initially shrugged off the assassination
by Gavrilo Princip of the heir to the Austrian throne, the Archduke
Franz Ferdinand, in the Bosnian capital Sarajevo on 28 June
1 9 1 4 . Not until 22 July did the financial press express any serious
anxiety that the Balkan crisis might escalate into something bigger
and more economically threatening..."
Of course it's mostly anecdotic evidence but it should serve as an counterargument to overwhelming expectance of war. Even members of elite didn't anticipate it. With our hindsight it's easy to disregard their views as foolish but they were simply being rational as the war really bankrupted the nations involved, bar USA of course. However, their militant contemporaries obviously pursued other goals than omnipresent prosperity.