Russian Ambassador to United Nations Vitaly Churkin, seen here in 2008, has said the Security Council should not get involved in Jordan, and it might make better sense to send a U.N. technical expert on refugees or humanitarian affairs. (DAVID KARP/AP)

With the ­Syrian refugee population swelling in his home country, Jordan’s envoy to the United Nations made a desperate plea during a meeting of diplomats last month: Visit the squalid camps and help Jordan cope with the crisis.

Russian U.N. Ambassador Vitaly Churkin, taking to the floor, had other ideas. He suggested that it might make better sense to send a U.N. technical expert on refugees or humanitarian affairs. As Churkin got up to leave, Susan E. Rice, the U.S. ambassador to the United Nations, pulled him aside.

“Are you going to block this?” she asked, according to a diplomat who overheard the conversation. “Well,” he replied, “you always block trips to Palestine.”

In the end, Churkin made it clear that he was not prepared to respond favorably to a call for help from a close U.S. ally. “We didn’t see that the Security Council should get involved,” he said in an interview, citing concerns that the visit might eventually lead to the establishment of humanitarian corridors or no-fly zones, “essentially dragging Jordan into the Syrian conflict.”

The episode underlined persistent Russian and American divisions over the response to the war in Syria. More broadly, though, it provided an intimate glimpse into the United States’ often prickly day-to-day working relationship with its former Cold War rival — a relationship in which efforts to advance shared interests are often spoiled by long-held grievances.

The big-power squabbles mask the degree to which American and Russian diplomats have come together to address major security threats, sanctioning the Iranian and North Korean nuclear programs and supporting initiatives aimed at checking the spread of Islamist extremism. On Syria, Washington and Moscow agree on the need to keep radical Islamists out of power, and neither side wants the United States to be drawn into the war.

Nonetheless, on a range of issues, Russia has used its power in the Security Council to act as a bureaucratic spoiler, complicating or in some cases burying American- and European-backed initiatives in a thicket of U.N. rules and procedures. The effort, according to diplomats, is part of a strategy by Russia to limit the freedom of action of the United States and its Western allies, which still possess the ability and the inclination to intervene at will.

It also serves as a reminder that Russia could make life “vastly more difficult” for the West, said Richard Gowan, a U.N. specialist at New York University’s Center on International Cooperation. The Russians, he said, “know how to throw grit into the wheel.”

Despite the dispute over the Jordan trip, Russia and the United States have been engaged in intensive, and often cordial, behind-the-scenes negotiations on the future of Syria that culminated in a May 7 agreement between Secretary of State John F. Kerry and Russian Foreign Minister Sergei Lavrov to convene a peace conference in Geneva to bring the warring sides together.

‘Not a U.S.-Russia thing’

Churkin said that the disagreements with the United States are sometimes overstated and that many of Moscow’s sharpest differences are with Britain and France, which have advocated for foreign intervention in Syria. Last weekend, he blocked a Security Council statement condemning the Syrian government’s brutal siege of the strategic town of Qusair, saying it was “not balanced.”

“It’s not a U.S.-Russia thing,” Churkin said. “We see the U.S. being more cautious and more careful” about the risk of foreign intervention in general. On Syria, Churkin added, the United States is “more realistic” and “less simplistic than some West European countries.”

He said Russian Deputy Foreign Minister Mikhail Bogdanov would begin talks Wednesday with top U.S. officials to settle issues ahead of the Geneva conference, including the selection of a slate of Syrian opposition representatives and invitations for outside powers.

“We are arguing that Iran should be invited; others are arguing that Iran should not be invited,” Churkin said. “We are in favor of having all those who can have influence.”

The dispute over Iran’s involvement is but one of a host of tension points between the United States and Russia. Russia also has pressed ahead with arms supplies to Syria despite firm warnings from the Americans not to do so.

Analysts say that Russia sees no reason to desist. If the United States and Europe decide to press ahead with their own weapons supplies, they will “be seen as undermining the peace process,” said Emile Hokayem, a Middle East analyst with the International Institute of Strategic Studies.

Russia’s approach is less a “crude power play” than a broader defense of its role in the world, Hokayem said. “There is no morality in Russian foreign policy, but there are principles: the principle of nonintervention and noninterference to protect Russian power and prestige and to allow it to conduct no-nonsense business with whomever it wants,” he said.

Points of contention

At the United Nations, Russia has a long list of grievances outside Syria, from the West’s push to recognize Kosovo, a territory of Moscow’s Serbian ally, to its history of overthrowing governments in Iraq, Afghanistan and Libya, generally with little regard for Russia’s preferences. Russia is convinced that Western powers, particularly Britain and France, are committed to using whatever parliamentary maneuvers they can in the Security Council to hasten the overthrow of Syrian President Bashar al-Assad.

“They are afraid the camel might slip its nose under the tent,” said one U.N.-based diplomat, who like some others spoke on the condition of anonymity to be candid.

Churkin has taken a certain pleasure in needling Rice, his American counterpart.

He has routinely thwarted her efforts to build political support in the Security Council for U.S.-led diplomatic initiatives on Sudan and South Sudan.

In March, the Russian envoy effectively derailed an effort by Rice to rally support for a Security Council statement urging South Sudan and Sudan to implement a set of agreements to define their separation. The objection was based not on any Russian opposition to the pacts but on the statement itself, which denounced Khartoum for launching an aerial bombardment campaign against targets in South Sudan.

“Compared to the Cold War days, the political and security differences between the United States and Russia are not nearly as deep these days. But sometimes it’s hard to tell by all the public acrimony between them in the council,” said Edward Luck, a historian and dean of the University of San Diego School of Peace Studies. “In some ways, the council serves as a public stage for acting out differences that sometimes don’t run that deep.”

Despite their differences, Churkin said he and Rice “have a very good personal and working relationship. Sometimes we have clashed, and sometimes we have clashed in a nasty way. . . . Do I do it on purpose? Of course not.”