What happens when the sacrifice is clear, but the reason isn’t?

How much does having a reason change what we’re capable of enduring? What happens when there’s no clear end date, no finish line, and the explanation keeps changing?

After reading Viktor Frankl’s Man’s Search for Meaning, I couldn’t stop thinking about the sailors aboard the USS Abraham Lincoln, my own time in the Navy, and the old idea that every service member writes Uncle Sam a blank check.