There were many reasons. For starters, it involved getting rid of a large number of Native Americans, and while some supported this, others opposed it as they were peaceful. Another thing was that this meant the introduction of new states and it deepened the division based on whether the states should be slave states or non-slave states. Also they involved war with Mexico and some wanted this and some didn't.
A possible reason was the attacks on them by crusaders and mongols around the 11th and 12th centuries. Another reason could have been the Arab rulers removing taxes from non Muslims and doing other things that hurt there income.
There were several major factors that led to stalemate in the trenches, but the best options from the list are "Defensive weapons were better than offensive ones.
<span>and Trenches were designed for defense."</span>
It limited a President to two terms.
