Explain in two paragraphs what caused world war i to begin

he direct cause of WWI was the assassination of Archduke Franz Ferdinand at Sarajevo on 28 June 1914. However historians feel that a number of factors contributed to the rivalry between the Great powers that allowed war on such a wide-scale to break out.

A major historical debate still rages about who has the ultimate responsibility for the outbreak of war. Germany and Austria are usually regarded as the main culprits. However unlike World War Two there is no one easily identifiable bad guy!

to act quickly in times of danger to the united states

because you have to act quickly if you want to live/survive.