I think they are talking limiting legal immigrations - reducing the number of immigrants legally allowed in a year. Not illegal like our Mexico border problem.
“...brought threats of retaliation Monday from leaders across the continent.”
In other words: “We don’t care if your people want immigration curbed. You will not curb immigration or else!”
If they cave, they are no longer a sovereign country whose people decide what kind of country they want.
Switzerland is not "rightwing," it is merely sane -- by a half a percent.