I believe the correct term to fill in the blank would be rumination. Trey is engaging in a practice of rumination. It is a deep or focused thinking of one that has undergone distress. It is analogous with depression and anxiety. When one is ruminating, he keeps thinking of a certain thought repetitively without thinking of any solutions to that problem.
The blazing hot sand in the Sahara desert
The Shiites believed that Ali of Muhammad’s cousin and son in law should be the leader.
The Sunni’s believed that Abu Bakr, his father in law, to be the leader.
They had to choose a new leader as Muhammad died in 632CE and they were attempting to decide their new ruler, soon leading to a division on who they would choose.
Hope this helps!
One factor that would be problematic for European Powers in their quest for having power over Mexico was the support of the US, which had its interest in showing European countries that they should not try to intervene in America's affairs. At the time however, the US was occupied with the Civil War, so Napoleon believed that his invasion could be successful.
