Long term shortages are evidence of supply controls or price controls. If nurse compensation was allowed to rise to its natural level the shortages would solve themselves. High compensation pulls people into a profession. Suppressing compensation with imported labor cures a short term problem but creates a bigger long term problem.

In this case, it's the evidence of the failing education system or misplaced incentives.

You also are missing another possibility, the nurse jobs can just disappear and patients will be left with worse care.