With two congressional delegations having visited Damascus since the US presidential election, Barack Obama appears to be keeping his promise to engage with Syria as part of his regional diplomacy strategy. The heads of the foreign relations committees of both the House of Representatives and the Senate met the Syrian president, Bashir al Assad, purportedly to gauge the country’s openness to negotiation. The delegate from the US Senate, John Kerry, expressed effusive praise of Mr Assad, saying that he conveyed a willingness to facilitate reconciliation between the rival Palestinian factions, Hamas and Fatah.

The visit by the US legislators could be the first step towards a warming of diplomatic relations between Washington and Damascus, which had been frozen with the withdrawal of the US ambassador in 2005 in protest at alleged Syrian involvement in the murder of the Lebanese politician Rafik Hariri. Mr Obama probably hopes that improved relations with Syria would encourage the country to cease its support for Hizbollah and Hamas, increase its border security with Iraq and drive a wedge between Damascus and Tehran. However, all this has been tried before through diplomatic channels with little effect.

In particular, Syria’s ties with Iran are more than ideological. Tehran provides much needed financial aid and trade relations for a country under stifling economic embargoes. Without some financial incentives in the form of aid money or a reduction in trade barriers, there is little to coax Syria in from the cold. However, with oil prices as low as they are, Damascus is undergoing painful budget cuts. The country desperately needs to join the global trade in goods and services and to boost its promising tourism industry.

There are additional incentives for Damascus to strike a deal, now more than ever. Its bargaining chips are dwindling. With security in Iraq rapidly improving, Syria cannot offer to stem the flow of insurgents over its porous border with Iraq. Although Ninevah, the Iraqi province that abuts Syria, remains a hotbed for insurgent activity, US intelligence has progressed to the point where the majority of would-be insurgents that cross the border are immediately detained by security forces. And a rapidly decreasing level of popular support for these militants diminishes their potential to foment unrest in Iraq.

Additionally, the longer that Syria supports ultra-hardline groups such as Hamas and Hizbollah, the more it risks alienating both itself and its supporters. This would ultimately reduce its regional clout, which is the entire point of supporting these groups in the first place. For example, Mr Assad’s harbouring of exiled Hamas leaders has contributed to a fracturing within the Palestinian organisation with a growing divide forming between the group’s leadership in Damascus and in the Gaza Strip. Pushing the likes of Khaled Meshaal towards an even harder line might lead to his being sidelined within Hamas.

Ultimately, Mr Assad must fear that the US will come to an accommodation with Iran that would leave Syria in the diplomatic cold without support from Tehran. This would require it to make even more painful concessions to reintegrate itself into the international community. And this is Mr Obama’s ultimate leverage. Syria can do much to aid the cause of Middle East peace. It can also do much to halt those efforts. But its ability to do so is steadily decreasing.