The Americans went into afghanistan for the ultimate purpose of creating a client state on the border of Iran.
Then it was a total failure, they have just poured money in what in effect was a temporary crook state on the verge of being a client state of Pakistan.
In the long term: Masses of refugees sweeping through Europe,
So, tuesday. Both in general and from Afghanistan specifically, refugees were Europe's problem since decades. The core of the problem is Europe's own policy, as for not mysterious at all reason so many refugees choose Europe in favor of geographically closer and more culturally similar countries.
severe disruption of maritime trade,
What the hell does landlocked Afghanistan of all things have to do with maritime trade?
swathes of territories in the ME and Africa falling into China's sphere of influence, emboldening it elsewhere and potentially igniting a war with the US,
Yeah, some extreme isolationists may want to go that far, but i think USA should pick its battles in that regard. Defend what's defensible and worth defending, not everything. Afghanistan is not one of these things.
mass terrorism on European and US soil,
Most of it domestically based, ironically. If they don't want terrorism they should deal with the immigration problem, both first and later generations. Which in turn is completely independent of anything that happens in ME. Why doesn't Japan have an islamic terrorism problem?
countries being reluctant to cooperate with the US militarily, and probably more besides.
Being compliantly led by the nose by Pakistan promotes a kind of cooperation USA should never want. Tolerating and even rewarding treachery for decades in fact makes USA look soft and lose respect. With allies like Pakistan and Afghanistan, USA needs no enemies.
No, we are being flooded with refugees because the wars destablised the region. Europe never had a problem in this scale until the invasions of iraq set the dominos toppling.
The region was never stable to begin with. The flood of refugees came because they saw what awaits them and they liked it more than the alternative options. And what did they see? Merkels and NGOs of Europe inviting them and showering them with caring rhetoric and taxpayer funded welfare. They saw it, they liked it, and they came for their dole.
If Europe wants to not have this problem it needs to start doling out something less encouraging.