Nessie: The passage is not very well written. "making tough calls" means to make difficult decisions, in particular, decisions that might have negative consequences for many other people. "psychological reserves" to me means to not to worry excessively, to be able to make decisions and not let those decisions affect your mental well-being.
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nessie000What does 'psychological reserves' and 'make tough calls' mean?Probably about the same as "guts." Depth of emotional and intellectual strength and stamina - health, balance.