The conflict in Afghanistan remains a stalemate between beleaguered Afghan security forces and the Taliban, but momentum has shifted to the latter. Taliban militants now control or contest more than 40 percent of the country. In rural areas, the Taliban have rolled out shadow governments that tackle everything from land dispute mediation to crime-fighting. Afghan troop losses are so large that entire units are getting replenished.

Now completing four months in office, President Trump has done little with Afghanistan, apart from reveling in his use of an 11-ton bomb on an Islamic State tunnel network in the eastern part of the country. And there's no evidence that made any major dent in the militant group's presence there.

Trump's generals have urged him to sign off on sending more troops to Afghanistan. In February, they asked for at least 3,000 U.S. soldiers to be added to the 8,400 there now. Those extra troops would help train Afghan security forces and advise them on the front lines. The Pentagon request remains on the table, and Trump may announce his decision before his visit to a NATO summit in Brussels on Thursday.

We hope he listens to his generals. But Trump must also realize that more combat likely won't end this war. Afghanistan can only get peace through a negotiated settlement with the Taliban. The president's policy for Afghanistan should have at its core a strategy for getting the Taliban to the negotiating table. Not an easy task, and one that requires three objectives:

• With guidance from U.S. and NATO troops, Afghan security forces not only need to halt the Taliban's momentum but to hurt the insurgency enough that Taliban leaders see merit in sitting down for peace talks. There's no incentive right now for them to talk. They've made sizable gains, and have even temporarily held cities such as Kunduz in the north. They've survived the years when America had as many as 100,000 troops in the country, and now their opponent is a poorly trained, poorly led Afghan army backed by an inept, fractured national government.

• Pakistan has a long-standing relationship with the Afghan Taliban, and can play a critical role in getting insurgent leaders to agree to talks. Taliban leaders have been able to survive for so long in part because Pakistan has always provided them secure refuge on its side of the border. Trump's policy must include outreach to Pakistan, and he can get Islamabad's attention by tying future military aid to that country to its help brokering Taliban peace talks.

• Finally, Afghanistan's unity government has to start cleansing itself of corruption that taints society from top to bottom. Taliban shadow governments appeal to Afghans because the alternative is an Afghan government always on the take. Paying bribes remains the norm for any Afghan who wants a crime or civil dispute resolved. Though the Taliban still are defined by their brutality, their brand of justice and dispute-handling comes free of charge. The Trump team's interaction with Kabul must include a strategy for purging corruption from governance.