France facing an invasion on several fronts in 1890

What if Spain, Germany, and Italy invaded France in 1890 after a nationalist assassination?

France is expected to suffer badly, especially under the added assumption that its government refuses prosecution and receives no outside help.

The scenario gives France simultaneous enemies in Spain, Germany, and Italy after an assassination provokes retaliation. France is expected to struggle, with its defeat in 1870 used as the comparison. A French government refusing to prosecute those responsible is also assumed to find little outside help. That additional condition explains the predicted diplomatic isolation.