Why do calamities befall Muslims but not disbelievers, even though corruption is widespread in the lands of disbelief?

Allah the Almighty is Wise and All-Knowing. His respite for the disobedient and disbelievers is a form of gradual enticement (istidraj) for them, as Allah the Almighty said: ﴿So when they forgot that by which they had been reminded, We opened to them the gates of every [good] thing until, when they rejoiced in that which they were given, We seized them unexpectedly, and behold, they were in despair.﴾ [Al-An'am: 44], and He said: ﴿Do they think that what We extend to them of wealth and children Is [because] We hasten to them good things? Rather, they perceive not.﴾ [Al-Mu'minun: 55-56]. Thus, the comfortable life of the disbelievers is an enticement and a brief enjoyment, and then their abode is Hell. They suffer psychological distress due to their turning away from the remembrance of Allah, as Allah the Almighty said: ﴿And whoever turns away from My remembrance - indeed, he will have a difficult life, and We will gather him on the Day of Resurrection blind.﴾ [Taha: 124]. And a great punishment in the Hereafter awaits them.