If any external force tried to "fix" the US it would result in stubborn revanchism and a deeper slide into corruption. To grossly generalize - the American culture of self-reliance means that any imposition of order, even if positive, would be rejected by most of the population (which is somewhat fair, since external impositions do compromise sovereignty).
If a good outcome is to happen - it needs to be driven and supported domestically.
If a good outcome is to happen - it needs to be driven and supported domestically.