U.S. Secretary of State John Kerry in Rome on Thursday. (Alberto Pizzoli/AFP/Getty Images)

When President Obama visits the Netherlands this month, it’s unlikely that an American ambassador will be there to meet him at the plane. And when he travels to Saudi Arabia on the same trip, he probably won’t be met by his choice for ambassador there, either.

The White House’s nominees to fill those diplomatic jobs and dozens of others have waited weeks or months for Senate confirmation before they can begin work. Their fate has become a proxy fight in a larger contest between both parties over control of the Senate schedule, and a growing diplomatic headache.

“It’s unacceptable that so many of our nominees — countless numbers of ambassadors to very important countries — are awaiting confirmation,” Secretary of State John F. Kerry said last week. “Our national security is not served by keeping many professionals — people who have waited patiently — in a perpetual limbo.”

About 50 ambassadorial nominees are awaiting votes by the Senate, far more than is typical. Democrats assert that the delays are payback for their historic decision in November to eliminate filibusters for most presidential nominees, making the tussle one of the most tangible consequences of the “nuclear option.”

Regardless of the reason, however, diplomats say foreign governments are noticing the empty desks.

At many U.S. embassies, nobody's home

“They all feel it’s directed at them,” no matter how often U.S. officials explain the underlying political turf fight, said Roberta Jacobson, the top State Department official for Latin America and Canada. “They cannot help but feel this is personal.”

Most recent public attention to ambassadors has focused on ill-prepared nominees with thin diplomatic credentials but strong political ties to Obama. The majority of those who are awaiting votes, however, are career diplomats whose selection is not controversial.

Eleven of 28 ambassadorial posts in Jacobson’s region are empty, including close ally and neighbor Canada. There is unusual tension between the United States and Canada now over the future of the Keystone XL oil pipeline, which Canada wants Washington to approve, and the administration’s nominee for Ottawa, Bruce Heyman, is not there to help manage it, Jacobson said.

“The ways of the U.S. Senate are always passing strange, so who knows why Mr. Heyman remains in limbo,” Globe and Mail columnist Jeffrey Simpson observed last month. “But it does not appear that President Barack Obama’s administration has used any muscle in that chamber to get an ambassador to Canada, nor that it has much time for Canada or Prime Minister Stephen Harper’s government.”

In Africa, 10 of the 40 ambassador posts are vacant.

“It sends a negative signal to these countries that we have not put our ambassadors on the ground,” said Linda Thomas-Greenfield, the top State Department official for Africa.

The delays can upend nominees’ lives and careers, forcing Foreign Service officers to find temporary housing and placeholder jobs while waiting for confirmation. Such disruption is less for political nominees — the term applied to donors or others picked from outside the Foreign Service.

Joseph Westphal is an Obama supporter named Nov. 7 to be the next ambassador to Saudi Arabia. He was supposed to have a hearing in December, but it was canceled because of the dispute between Democrats and Republicans in the Senate, said Gerald Feierstein, the No. 2 official in the State Department’s Mideast bureau.

The key post in Riyadh has been empty for months, while U.S.-Saudi relations have suffered a rough patch over Saudi complaints that Obama isn’t doing enough in Syria and elsewhere.

“We’ve gone through a period where there’s been some misunderstanding” about U.S. commitment to engagement in the Middle East, Feierstein said. To the Saudis, the lack of an ambassador “only reinforces this sense that the U.S. is disengaging from the region.”

The rule change approved by Senate Democrats allowed most federal judicial nominees and executive branch appointments to advance to a final confirmation vote by a simple majority of senators, rather than the 60-vote threshold that had been the norm for the last four decades.

Democrats, who control the chamber, said the change was necessary to fix a broken system. But the effect is to give a president whose party holds the majority in the Senate near certainty that his nominees will be approved, with far less opportunity for political obstruction.

Republicans are responding by playing with the procedural rules, Democrats claim. Instead of allowing large batches of nominees to be approved by “unanimous consent” without debate — as has been the norm for years — each nominee may have to be considered individually by Republicans who refuse to accelerate the process. That has the effect of greatly slowing down an already cumbersome process.

Sen. Bob Corker (Tenn.), the top Republican on the Senate Foreign Relations Committee, said the change to Senate rules prompted “a death spiral” that continues today.

Corker said Majority Leader Harry M. Reid (D-Nev.) could have helped get a batch of 40 or more ambassadors approved last fall if he hadn’t moved for the rules change.

“He’s slowed that down by the action he’s taken,” Corker said. “Most all of them would have been approved if we had not embarked on the nuclear option.”

Republicans angrily note that the long waiting times since many of Obama’s ambassador picks were named — more than 200 days in many cases — include many months before the nuclear option showdown. If Democrats had moved more quickly in 2013, most of those jobs would be filled, Republicans said.

“If Senator Reid hadn’t manufactured a crisis and changed the rules, this wouldn’t have happened,” Sen. Lamar Alexander (R-Tenn.) said. “He brought this all on himself, and it’s all his fault.”

Frustrated by the continued delay, Reid threatened last week to call for votes on all of Obama’s remaining nominees. “If that is what the Republicans want us to do, then that is what we will do,” he said.

Limited days of legislative business and a long list of political messaging bills designed to serve as election year fodder mean nominations aren’t a top priority. If Reid did call for votes on all pending nominees it could tie up the Senate for weeks, his aides said.

Corker, at a recent meeting with reporters hosted by the Christian Science Monitor, suggested Republicans “will continue to let the pressure out a little bit at a time” and allow votes on some nominees, but aides to Senate Minority Leader Mitch McConnell (R-Ky.) said no decision has been made.

Corker has been credited by the State Department and Senate Democrats for moving nominees quickly through the Senate Foreign Relations Committee. Despite his public anger, aides said Corker has spoken several times in recent weeks with Reid to find a way to break the impasse. His efforts prompted Kerry to send him a personal thank you note last week.

Regardless of the partisan tussle, the recent embarrassing performances by Obama political donors make it harder to advocate for faster action on the backlog of other nominees, State Department officials conceded. The nominee for Norway, for example, seemed unaware of the makeup of that nation’s political leadership.

“It’s the first thing people think of” when the topic of pending ambassadors comes up, said one State Department official who spoke on the condition of anonymity. “We know it’s bad, but it’s not the real problem.”

At least one State Department nominee was confirmed this week. After voting to confirm new district court judges on Thursday, senators quickly confirmed Rose Gottemoeller to serve as an undersecretary for arms control. She had been waiting for approval since Sept. 11, 2012, more than 540 days.