5 United States 78% 1990
6 Australia 75% 1990
=7 Switzerland 74% 1990
=7 United Kingdom 74% 1990
9 Netherlands 69% 1990
US fifth with Vietnam almost a generation behind and long before Iraq/Afghanistan. Britain post-Falkland was also quite high. The Brits had second highest per capita loss in Afghanistan and also high per capita loss in Iraq.
It is interesting that the Netherlands were actually in top 10 back then, and they have not had the same losses in overseas operations as Britain and Denmark.
The humiliation in Srbrenica shouldn't be that influential. Again I think that the lack of a realistic threat to the homeland is crucial, still the collapse in willingness to fight has been far larger in the Netherlands than in other similar countries.
Never ever mention Srebrenica to a Dutchman.
And it's not as if that's the only reason for Dutch national confidence to take a bit of a fall over the last 25 years.