Not just the country also the world.
If I was a healthy student, I wouldn't be worried. Statistically, their risk is very low. The people that should be worried are professors, student interacting university staff, students with preexisting conditions, and the community.
That said, the real issue is schools/universities/dorms are ideal places for coronavirus to spread. Try to do contact tracing on campus. If someone in Wads had it, the whole dorm would be covered/exposed in a matter of hours. This stuff lives on nonporous surfaces (under room temp and no UV light) for days.
The biggest issue, how many ICU patients can the UP heath system handle? Would you want to wait 2 hours to get to Marquette if you couldn't breath? Would Marquette have enough beds because NMU students returning would introduce the same risks. One could argue there should be more medical resources available to help and better treatment protocols to improve survival rate and reduce overall system capacity/improve recovery rates.
Then there is the risk to the economy as well. They can't keep the students away forever (ie until a vaccine is approved and distributed).