For months, Turkish officials have said repeatedly that they would never accept a Kurdish takeover of the northern Iraqi oil cities of Kirkuk and Mosul. This was a "red line," they said, one of several that would trigger a Turkish invasion of northern Iraq if crossed.

But with thousands of Iraqi Kurds, mostly civilians, streaming into Mosul today, and the Kurdish fighters who seized Kirkuk a day earlier now established there, the only Turkish soldiers who have crossed the Iraqi border are 15 officers assigned to work with U.S. troops as military observers.

In effect, said Bulent Aliriza, a Turkey scholar at the Center for Strategic and International Studies in Washington, "the Turks blinked. They blinked big time."

Earlier this week, a senior Turkish diplomat said there was "no flexibility" in Turkey's position, warning that even a move by unarmed civilians into the cities would be a provocation. A senior Turkish military official went further, telling reporters that one Kurdish fighter spending one hour in either city would draw a military response.

But for two days now, Turkey's leaders have been trying to play down developments in northern Iraq -- developments they had said would be a threat to national security. Prime Minister Recep Tayyip Erdogan has ignored northern Iraq in his speeches. The chief of the military, Gen. Hilmi Ozkok, has made no public statements. The task of explaining Turkey's position has been left instead to Foreign Minister Abdullah Gul, who focuses on U.S. promises that the Kurdish fighters will leave Kirkuk and Mosul, cities they have waited years to capture.

"Our sensitivities are clear," Gul said today after a meeting of the nation's top military and civilian leaders. "A backward step is out of the question."

But in reality, the government is stepping back from previous threats of a military incursion, which the Iraqi Kurds had threatened to resist and which would have seriously damaged relations with both the United States, a key supporter of Turkey's fragile economy, and the European Union, which Turkey desperately wants to join.

Instead, Turkey has decided, at least for now, to rely on the United States to address its security concerns in northern Iraq -- a humbling setback, considering that U.S. officials already have failed to live up to their promises to keep the Iraqi Kurds out of Kirkuk and Mosul.

Many Turks believe the United States never intended to keep those promises. While Secretary of State Colin L. Powell and other diplomats assured Turkey that U.S. forces would capture the cities without Kurdish forces, they refused to sign a written guarantee, saying they needed to preserve "operational flexibility" for the U.S. military. At the same time, the Pentagon never rushed to move large numbers of U.S. troops into northern Iraq, where the Iraqi Kurds had offered the services of their 70,000 pesh merga fighters.

"The Americans gave our guys the message, 'You can't [enter northern Iraq,]' but they said to the Kurds, 'Never mind about the Turks,' " said Oktay Eksi, a columnist for Hurriyet, Turkey's largest newspaper. "Almost none of the statements made by Turkish officials have been realized. By comparison, almost all the statements of Iraqi Kurd leaders have come true."

So far, most of the Turkish news media have blamed their government, not the United States. After Gul's statement today, journalists challenged him to explain what one newspaper headline described as "The Kirkuk Disaster."

They asked what Turkey would do about the destruction of land records in Kirkuk, which would make it easier for Kurds to cleanse the city of the Turkmen minority that Turkey had vowed to protect. And they wanted to know whether Turkey issued any deadline for the Kurdish fighters to withdraw. Gul could say only that the government was monitoring the situation.

" 'We are hoping. We wish . . . .We hope that,' " wrote Mehmet Tezkhan, a columnist for the newspaper Sabah, characterizing the language used by the government. "You will ask what these words are. Let me tell you immediately: The new rhetoric of Turkish foreign policy," he said. "There is nothing else that Ankara can do other than hope."

Many analysts argue that Turkey brought the crisis on itself by rejecting the plan to let up to 62,000 U.S. troops use Turkish territory to attack Iraq. "Now we are suffering for this," wrote Mustafa Unal, a journalist at the Islamic-oriented newspaper Zaman. "If the resolution had been accepted, American troops would have dominated the region. There would have been no room left for Kurdish groups in northern Iraq, and according to the agreement, Turkey would have dispatched forces to northern Iraq."

Cuneyt Unsiler, a prominent writer on military affairs, said the United States essentially was "taking revenge" on Turkey for its refusal to host U.S. troops.

"The United States, if not directly, then indirectly, is telling Turkey: 'Sorry, the Kurds helped me more than you did, so I have to work with them,' " he said. "I don't think the pesh merga will be allowed to rule Mosul and Kirkuk, but on the other hand, it's impossible to say they will have no political power over these two cities."

Unsiler said Turkey's "red line has been erased," and the credibility of both the government and the military has been damaged. "I think everybody in Turkey is going to ask whether our strategic concepts were correct," he said. "Our neighboring countries will also start questioning our policies."

Turkey has consistently opposed Kurdish control of Kirkuk and Mosul because it fears the Kurds would use the cities' oil wealth to establish an independent Kurdish state and revive a violent separatist movement among its own Kurdish population. But several analysts said the government could be forced to reevaluate that position now.

In an article today in the newspaper Radikal, the columnist Ismet Berkan described the U.S. promise to remove the Kurds from Kirkuk as "only a consolation. When Iraq is divided into three federal regions, both Mosul and Kirkuk will be in the Kurdish region. . . . There is no way to stop this process."

"It would perhaps be better if Ankara gave up building its policies on red lines and fear and instead begin accommodating itself to the unavoidable facts of the future," he added. "Throwing a military threat or sending armed forces to northern Iraq will not decrease Turkey's present or future problems. On the contrary, it will increase them. . . . It should not concern us who takes Mosul or Kirkuk."

At least one poll published in Turkey showed that a majority of Turks oppose sending troops into northern Iraq. Only 40 percent supported a Turkish invasion if national interests required it to do so.

Ferai Tinc, a popular writer on foreign affairs, said the Turkish government should address discontent among its own Kurdish population, offering greater cultural rights and economic opportunities, before worrying about northern Iraq. "All the Iraqi citizens are our neighbors," she said. "We don't have any right to dictate to them."

Turks in Ankara demonstrate against U.S. moves in the northern Iraqi cities of Mosul and Kirkuk. Turkish leaders have said they expect U.S. officials to resolve the situation.