I think most of the world saw us as an easy touch, and enough of the world saw us as an easy target that 911 happened.
The 90's saw steadily increasing terrorism against the US with no effective US response.
And our debt was no where nearly close to being conquered.
As to moral leadership, we did nothing in Rwanda, leading the way with the UN and france who also did nothing.
I frankly think that we had a very expensive 'feel good' period, as examplified in your post, that some are looking back on in fond nostalgia.
Please note that long before france screwed us and tried to extend the rule of saddam, the most popular book sold in france 'proved' that 911 was a US or Israeli plot.
Enjoy your rose colored glasses.
Ed