All these questions weigh on Turkey's leaders, who have enough on their hands without embarking on a foreign military adventure. Turkey is caught up in an internal rift between the Islamic-rooted government and the military-backed, secular establishment, less than two weeks ahead of July 22 elections that were called early as a way to ease tensions in a polarized society.

A military operation could disrupt Turkey's fragile democratic process by diverting attention from campaign topics such as the economy, and raise suspicion about whether the government and its opponents are manipulating the Iraq issue to win nationalist support at the polls.

On Monday, Prime Minister Recep Tayyip Erdogan said on Turkish television that Turkey would take whatever steps were necessary if the United States fails to fulfill its pledge to help in the fight against Kurdish rebels, but he appeared reluctant to order an invasion before the elections.

"We are seeing with great grief that America remains quiet as Turkey struggles against terrorism. Because there were promises given to us, and they need to be kept. If not, we can take care of our own business," Erdogan said. "We hope there won't be an extraordinary situation before the election. But there'll be a new evaluation after the elections."

The aim of any military push into Iraq would be to hunt separatist rebels of the Kurdish Workers' Party, or PKK, who rest, train and resupply in remote bases in the predominantly Kurdish region of northern Iraq before crossing mountain passes into Turkey to attack targets there. In recent months, rebels have stepped up assaults, adding to a sense of urgency in Turkey that something must be done.

A claim Monday by Iraqi Foreign Minister Hoshyar Zebari, a Kurd from northern Iraq, that Turkey had massed 140,000 soldiers on its border with Iraq rattled nerves on both sides of the border. Turkey's military had no comment, and the Bush administration said there has been no such mass buildup.

Although Turkish military commanders have said an invasion is necessary, it is difficult to know how prepared they are because many areas along the Iraqi border have been declared "security zones" and are essentially off-limits to civilians. There have been reports of Turkish shelling of rebel positions inside Iraq from time to time, and commandos are believed to periodically conduct so-called "hot pursuits" of guerrillas across the border.

Turkey also feels a special kinship for the ethnic Turkmen minority in northern Iraq, and Turkish military air ambulances on Sunday evacuated 21 people wounded in a devastating suicide attack in Armili, a town north of Baghdad, for treatment in Turkish hospitals. Turkey condemned the attack, but there was no indication that it gave impetus to calls for military intervention in the north to protect its ethnic brethren.

Turkey staged a series of major cross-border operations in the 1990s, involving tens of thousands of troops and jet fighters that attacked suspected rebels hideouts in the mountains. Results were mixed, with rebels regrouping after the bulk of the Turkish forces had left, even though some military units stayed behind to monitor guerrilla activities.

This time, Turkish forces could face the possibility of a confrontation with Iraqi Kurds who are emboldened by newfound autonomy since the downfall of Saddam Hussein in the U.S.-led invasion in 2003. Some U.S. forces are also in the area, with American warplanes known to fly close to the Iraqi-Turkish border.

Soner Cagaptay, director of the Turkish Research Program at the Washington Institute for Near East Policy, acknowledged that part of Turkey's goal was likely to draw increased U.S. attention to the issue, but said the Turks were likely to act if attacks continued.

Cagaptay said there are already Turkish forces in Iraq, operating about 10 to 15 miles beyond the border, where the steep mountains turn into hills that are more easily navigable. He said monitoring this area was "the only way (Turkey) could control the border."

Cagaptay said Zebari's announcement that there are Turkish troops on the border was likely a sign that the Iraqi foreign minister takes the threat of further incursion seriously and is trying to draw international attention to the border games to eliminate the possibility that Turkey could execute raids under the radar.

Besides possible tension with the United States, another concern for Turkey is the impact that a military intervention might have on its troubled efforts to join the European Union. Accusations of human rights abuses by Kurds could slow the process even further; the Turkish military has already expressed frustration with what it perceives as European leniency toward PKK sympathizers.

Sinan Ogan, head of the Turkish Center for International Relations and Strategic Analysis, said one option was a limited air force operation, which would help the government deal with domestic demand for action. If ground forces do go in, he said, the military would want them to stay for at least six months to assess the impact of the mission.

"An operation before the elections will bring the ruling government more votes so they might be willing to allow such an operation," he said. "A clash with several soldiers getting killed or a bombing at an important spot might be the spark for a military operation."