Sunni volunteer tribal fighters take part in a military training near the town Khalidiya, east of Ramadi, this month. (European Pressphoto Agency)

PRESSED ABOUT his strategy for fighting the Islamic State, a petulant-sounding President Obama insisted Monday, as he has before, that his critics have offered no concrete alternatives for action in Syria and Iraq, other than putting “large numbers of U.S. troops on the ground.” This claim was faulty in two respects. First, few if any White House critics are proposing a U.S. ground operation on the scale of the previous wars in Iraq and Afghanistan. At the same time, military experts both within and outside the administration have proposed more modest measures that could significantly increase the pressure on the Islamic State if the president were to adopt them.

Mr. Obama is right that the route to destroying the Islamic State lies in finding local partners in the Middle East and elsewhere who can stabilize their countries with U.S. and other international support. If that broad strategy is correct, however, its implementation has been consistently underpowered. U.S. aid to Iraqi and Syrian allies has been too small and too slow to arrive; airstrikes have been conducted at a fraction of the pace of previous campaigns.

The United States has not used its leverage to bring about essential political change, including the removal of Syrian President Bashar al-Assad and significant steps by the Shiite-led Iraqi government to reconcile with Sunni leaders. In response to failures, Mr. Obama has tended to escalate U.S. action in small increments unlikely to make a decisive difference — like his recent decision to dispatch fewer than 50 Special Operations troops to Syria.

What would make a difference? Numerous military experts have proposed that the United States stiffen the Iraqi forces attempting to retake the town of Ramadi, and Arabs and Kurds advancing toward the Islamic State capital of Raqqa , by deploying more Special Operations forces who could act as forward air controllers and advise on battlefield tactics. Mr. Obama could also send advisers to Iraqi battalions; currently, U.S. personnel operate only at the division level. More specialized U.S. assets, such as advanced drones, could be used to back local forces.

For more than a year, some experts have been urging Mr. Obama to begin the direct delivery of weapons, ammunition and other equipment to Kurdish forces in Iraq as well as Sunni tribal fighters. The administration has persisted in trying to route this materiel through the Iraqi government, only to see the deliveries slowed or blocked. The administration could begin direct deliveries while exerting more pressure on Prime Minister Haider al-Abadi to follow through on promises to reach political accords with Sunnis and Kurds.

Secretary of State John F. Kerry has helped to launch a diplomatic effort to end the Syrian civil war, but only by not making it conditional on Mr. Assad’s departure. Mr. Obama could order steps to increase the pressure on Mr. Assad in those talks, such as the creation of safe zones in collaboration with Jordan and Turkey where refugees and opposition forces could gather.

None of these measures would lead to the immediate collapse of the Islamic State or ensure that it did not carry out more attacks in Western capitals. They would, however, make it easier to build the local partnerships Mr. Obama says he seeks. Many present and former U.S. officials believe they are feasible. The president would be wise to set aside his defensiveness and reconsider them.