When World War I began in August 1914, many people anticipated that the war would end by Christmas of that year. Which event extended the war into 1915 and beyond?

I think the event that extended the war was when Russia declared war on Austria-Hungary as a sign of friendship to Serbia. Germany then declares war on Russia as a sign of friendship to Austria-Hungary. France as a sign of friendship then declares war on Germany. Britain as a sign of friendship declares war on Germany when they invaded their ally, Belgium.

Explanation:

where is the passage?

can't without the passage.

post the full question.