Apparently it wasn't Napoleon who said an army travels on its stomach. But surely the necessity of providing appropriate gear, food, water and other basics to troops was clear after his troops, freezing and dropping from starvation, staggered in retreat after the disastrous 1812 invasion of Russia. Of the 680,000 men Bonaparte took with him, fewer than 100,000 returned. Perhaps nothing that dramatic is about to happen in Afghanistan. But the warning signs of impending trouble are clear: the $57 billion U.S. investment in Afghanistan's security forces is at risk because the Afghans cannot supply, or resupply their troops, can't prevent their weapons and vehicles from breaking down and can't fix them when they do.
Much of what U.S. service personnel died or were wounded for will have been lost. Although extremely tragic, however, this bad outcome may not be the worst effect of the war. That would be the destabilization of nearby Pakistan, which has 100-200 nuclear weapons and an insurgency trying to overthrow the Pakistani government.
The candidates must accept the final results of the runoff, and remain open to working together in the next government. If the loser feeds a frenzy of public opposition, it could lay the groundwork for something like the civil war that tore the country apart and opened the door to Taliban rule in the 1990s.