There is a law that the govt has to negotiate in good faith. Presumably while they could say "no" to everything, it would be hard to prove that was "good faith" if the union takes them to court.
In the US, most public-sector unions incl. transport workers are essentially not allowed strike under the Railway Labor Act unless they have exhausted all mandatory federal negotiation/ mediation (nominally on the grounds that it could cripple the economy).
This was also an issue in the 2022 US freight rail labor dispute where Biden, Pelosi and Congress passed a law to criminalize the prospect of rail strike. [0][1]
If the freight staffing level cuts had been reversed, it's quite likely the 2/2023
East Palestine, OH train derailment and $$bn environmental disaster [2] would have been avoided. The freight companies, in the name of efficiency and slashing staffing levels, had combined multiple trains into one huge one (which has a higher risk of derailing, and larger size of derailment.)
To your question, it would be good if the US had a nonpartisan setup for balancing profit and efficiency vs safety and conditions, but that's not the case. Since the time of Reagan and the 1981 PATCO strike. Curious if there's any objective comparison between China and US how freight rail is operated. But then the Chinese freight rail is state-owned which largely removes the profit incentive for cutting safety. Compared to the US, China has almost no freight rail disasters, and it has more freight traffic.
