David Petraeus has warned the Trump administration against total withdrawal
of combat forces from Afghanistan. 

 Petraeus, a retired U.S. Army general who served as commander of U.S.
Central Command and of coalition forces in Iraq and Afghanistan and as
director of the Central Intelligence Agency, has warned that under no
circumstances should the Trump administration repeat the mistake its
predecessor made in Iraq.

He expressed these views in an op-ed co-written by Vance Serchuk, an
adjunct senior fellow at the Center for a New American Security, published
by the Wall Street Journal. The former general said the announcement of a
peace agreement between the U.S. and the Taliban is said to be imminent,
after years of combat and months of negotiation. The U.S. will reportedly
promise to reduce its military presence in Afghanistan in exchange for a
Taliban commitment to cooperate against international terrorism and enter
direct talks with the Afghan government.

It added for Americans as well as Afghans, any possibility of settling
this conflict is cause for hope. But even as citizens in both countries
pray for peace, leaders in Washington must proceed with caution. While
diplomatic progress with the Taliban may justify a reduction in U.S. force
levels, under no circumstances should the Trump administration repeat the
mistake its predecessor made in Iraq and agree to a total withdrawal of
combat forces from Afghanistan.

A complete military exit from Afghanistan today would be even more
ill-advised and risky than the Obama administration’s disengagement from
Iraq in 2011. Iraq had largely been stabilized by the time the last U.S.
combat elements left, with al Qaeda having been routed during the 2007
surge. In Afghanistan, by contrast, the Taliban are far from defeated,
while some 20 foreign terrorist organizations like al Qaeda and ISIS
retain a presence in the region. It is unlikely that any will join a peace
deal, it said.

The idea that the U.S. can leave if the Taliban promise to combat rather
than conspire with these groups is also wrongheaded. Until the Taliban
demonstrate they have both the determination and the capability to work
with the Afghan government against international terrorists—and there is
ample reason to doubt this—common sense dictates the U.S. must retain its
own means to pressure extremist networks plotting against the American
homeland and U.S. allies. This can be accomplished only by having some
number of capable American forces in Afghanistan, along with substantial
“enablers” such as unmanned aerial vehicles and close air support, the
article said.

It said the Taliban have clearly indicated what they will try to do once
U.S. forces are gone: overthrow the Afghan government and reimpose
medieval rule. Their resistance to a formal cease-fire, continued barbaric
attacks on civilians, and opposition to elections scheduled for this fall
are all warning signs. Such a conflagration is likely to reinvigorate the
flagging fortunes of Islamist extremism world-wide and the global
terrorist threat—which, despite the destruction of Islamic State’s
territorial caliphate in Iraq and Syria, is by no means defeated, it said.