This week, Iraq has drawn decisively closer to the two countries the US alleges are the greatest threats to peace and stability in the Middle East.
Tuesday, Syria restored diplomatic ties with Iraq that were broken by Saddam Hussein in 1980 back when Iraq was fighting Iran. Also Tuesday, Iraqi President Jalal Talabani's office said he would travel to Tehran this weekend to meet with Iranian President Mahmoud Ahmadinejad to talk about restoring order to Iraq.
The US has repeatedly accused Iran and Syria of stirring up violence inside Iraq, but recently the notion of isolating them as punishment has lost favor in Washington. A growing number President Bush's advisers are urging direct dialogue with both nations. They argue that engagement could convince Syria to do more to prevent foreign fighters from entering Iraq; Iran could exert more influence on Iraq's dominant Shiite political parties (and their militias) to compromise more.
"It could make a difference, but not a critical difference,'' says Anthony Cordesman, former director of intelligence assessment to the US Secretary of Defense and now a senior fellow at the Center for Strategic and International Studies (CSIS) in Washington.
Iran has been accused of being deeply involved in training, funding, and arming the two major Shiite militias in Iraq, where Tehran has historic ties to the current Shiite political leadership. Many Iraqi Shiites spent years in Iranian exile during Mr. Hussein's decades in power in Baghdad. One militia, the Badr Brigade, was trained in Iran by the Revolutionary Guard.
"While of course it's worth talking to them, even if they complied with all our wishes, what they could do probably would not be decisive,'' says Wayne White, former head of the Middle East desk at the State Department's Bureau of Intelligence and Research.
"The situation is so bad now in Iraq," he says, "you can't expect any magic over there. And even if you could get the Iranians and Syrians to accomplish things you wanted, what would you have to cough up in return?"
Former US Secretary of State James Baker, who served under President Bush's father and is now the leader of the Iraq Study Group (ISG) advising the president on new directions for his Iraq policy, has been quietly meeting with Syrian officials in the US, according to an interview with the Syrian ambassador to the US reported by The New York Times. He also met with Iran's ambassador to the United Nations.
British Prime Minister Tony Blair has publicly called for more direct engagement, and members of the ISG have been quietly urging more direct ties with Iran, as well.
Outgoing US Secretary of Defense Donald Rumsfeld, a hard-liner on Syria and Iran, was ousted this month in favor of former CIA chief Robert Gates, who as a member of the ISG had also been urging direct engagement with Iran over the problems in Iraq.
Though Mr. Blair praised the Syrian visit to Iraq, saying it may see that "Syria becomes of help to Iraq in its process of progress ... rather than a hindrance," the closer ties between Iraq and Syria could quickly become a strain on the US and Iraqi relationship.
Meanwhile, Iran's meeting with the Iraqi president this weekend is seen by some analysts as evidence of its increasingly muscular role in the Middle East, where it already has established deep influence in Syria and Lebanon.
Lebanon is yet another nation where various internal and external political forces are vying for power. On Tuesday, a leading anti-Syrian Lebanese politician, Pierre Gemayel, was assassinated in Beirut. An ally of his, parliament leader Saad Hariri, immediately claimed that Syria was behind the murder.
Mr. Hariri's father, Rafik, a former prime minister, was assassinated last February, and the US and anti-Syrian Lebanese politicians have blamed Syria for that murder as well, which they allege was designed to bolster the pro-Syrian, Iran-backed Hizbullah inside the country.
Mr. Cordesman says events like the Gemayel assassination in Lebanon underscore the likelihood that neither Iran nor Syria will become very cooperative on issues that the US cares about – withdrawing support from Hizbullah in Syria's case, or abandoning its nuclear program in Iran's case – any time soon.
"What everyone needs to understand is that cooperation from Syria and Iran is likely to be very limited, particularly in the short-term,'' he says.
"Syria is certainly backing the Hizbullah in its efforts to achieve a new level of political influence in Lebanon and it has the feeling that it's less vulnerable to any kind of US action now, ... and when Iran goes out and carries out the most provocative military exercise in recent history, this may not be a symbol of compromise." He was referring to recent Iranian military exercises in the Gulf.
The State Department reacted with skepticism about Iran's intentions in Iraq, but said it was up to Iraq to decide whether to attend. "It's their call; it's their decision," deputy spokesman Tom Casey said in Washington.
• Material from the wires was used in this report.