THAILAND’S MILITARY has staged at least 11 coups in the past 80 years, a record that has held the country back politically and economically. Whether its declaration Tuesday of martial law will add to that sorry score is not yet certain. In deploying troops, banning marches and ordering the shutdown of 10 radio and television channels, army chief Gen. Prayuth Chan-Ocha did not unseat the sitting civilian government; he said his intention was to prevent “riots and bloodshed” and promote negotiations between the country’s polarized political factions. The Associated Press quoted him as saying that he “will try not to violate human rights — too much.”

That’s not reassuring, particularly in view of the military’s record of siding against the populist movement of Thaksin Shinawatra, whom it overthrew in its last coup, in 2006. If the army’s intention is, as some fear, to facilitate an anti-democratic movement that wants to appoint an unelected government, then Tuesday’s events will qualify as another coup — and should provoke a strong reaction from the United States and other democracies.

On the other hand, if Gen. Prayuth is serious about playing the role of an honest broker, the military’s move could prove positive. After six months of increasingly bitter conflict, Thailand is desperately in need of a compromise. The struggle between the Thaksin movement, based in rural areas and the northeast, and the Bangkok-based traditional establishment has been sliding toward civil war. After the Supreme Court, sympathetic to the conservative elite, ousted the elected government of Mr. Thaksin’s sister Yingluck Shinawatra this month, his “red shirt” supporters have been massing outside the capital even as their opponents continue to occupy government buildings in their attempt to overturn the political system.

While daily life proceeded normally Tuesday in Bangkok, the turmoil is dragging down a once-booming economy: Thailand registered negative growth in the first quarter. There is no reason for this stagnation other than the inability of the pro- and anti-Thaksin forces to reach a political settlement that meets the legitimate concerns of both sides.

The outlines of such an accord are readily apparent. In exchange for institutional reforms, including a devolution of power from the central government to the provinces, both sides should agree to abide by democratic elections — and schedule new ones as soon as possible. The principal obstacle to such a settlement is the anti-Thaksin militant group led by Suthep Thaugsuban, whose solution to the repeated election victories of Thaksin’s parties is to install an unelected government with a mandate to wipe out the movement. At best the military could use its clout to induce Mr. Suthep, or his supporters, to compromise.

The Obama administration, whose hesi­ta­tion to label Egypt’s military coup as a coup last year helped propel that country toward another dictatorship, has been sending the right message to Thailand. A State Department spokesperson said the administration expects the military “not to undermine democratic institutions” and underlined “the need for elections to determine the will of the Thai people.” If the generals do not respect those principles, the administration should not hesitate to apply U.S. law mandating the suspension of military aid and cooperation.