Losers of war pay these to make up for damages they caused

The answer would be reparations

Large death tolls and no resolution

Trench warfare creating stalemates with men stuck in trenches for weeks or months at time. Going "over the top" was dangerous due to machine gun fire and the trenches themselves were germ-ridden. 

Also due to the stalemates, if continued a peace could be brokered but with no clear winner. This would lead to little resolution on the issues presented and perhaps not allowing for resolution of serious concern Europe had going into the war.