Bush backed them, America loved them, but what awaits the McCartneys in Belfast?

The McCartney sisters got all the best invitations and headlines on their trip to Washington, but as they return home to a divided city they must be asking themselves: what have we really achieved?

They have met the most powerful man in the world and told him their story. But as the sisters and partner of the murdered Belfast man Robert McCartney travel home today from America, they will be wondering what exactly their high-profile visit to the White House has actually achieved.

True, the US President can now put six human faces to a problem he has largely ignored so far. Gerry Adams, president of Sinn Fein and a regular visitor to the White House on St Patrick's Day, did not get an invitation this time. And the IRA has fewer supporters in the States than it did a week ago - before the articulate sisters told their story and challenged misty-eyed Irish Americans to give up their support for armed struggle.

"The sisters have turned the republican movement inside out," said one observer back home in Belfast. Both Sinn Fein and the IRA have urged their members to reveal who killed Robert McCartney in a bar there eight weeks ago. But so far nobody has, at least publicly. For all their talking, the McCartney women are no closer to what they really want: convictions for the men who killed their brother.

"The response we have been getting from the people we have seen has been good," said Catherine McCartney, a teacher. "But what matters to us is what happens on the ground back home. It is ironic that we have had to leave our country to try and get justice."

The sisters are now trying to decide whether one or more of them should stand for the local elections expected in Belfast in May. Standing may keep their campaign from running out of steam - but it could also lead them into a party political quagmire.

Almost every participant in the peace process is sympathetic to their aims, but they also have their own agendas. London, Dublin, Washington and Ian Paisley's Democratic Unionist Party all hope that republicans will continue to feel undiminished heat from the McCartneys.

Yet, underneath all the furore, the central, underlying assumption of the peace process remains unaltered: that it will continue with republican participation, and that Sinn Fein and Mr Paisley will, sooner or later, get back to the table to hammer out agreement on a new Belfast administration.

To the surprise of many, all the recent turmoil over IRA involvement in the murder and the £26m robbery of the Northern Bank has not caused Mr Paisley to slam the door on a future deal. He and Sinn Fein are likely to be the big Northern Ireland winners in the looming Westminster election. The clearest sign of this came when George Bush, while refusing to meet Mr Adams, refrained from stern condemnation of Sinn Fein.

Mr Paisley and the three governments hope to have the IRA agree to renounce all criminality, preferably before the next round of negotiations begins. The ideal would be a declaration from the IRA that it is disbanding. The high-level strategy is therefore to use the McCartney campaign to batter republicans into making extensive concessions.

The bizarre IRA offer to shoot republicans involved in the murder was followed last week by another error from Martin McGuinness. He publicly warned the family against being manipulated by others for party political purposes - a statement some interpreted as a veiled threat, which he denied. The republican counter-attack has taken the form of hints that the sisters are being manipulated, together with allegations that the police investigation is "driven by political considerations rather than justice".

Unless IRA members actually come forward with confessions, most believe it will be extremely difficult to bring charges in the case. Although IRA and Sinn Fein personnel have been interviewed by police they have exercised their right to silence, staring at the wall and saying nothing.

By doing so, the key suspects are disobeying IRA orders, which is always a risky business. But giving a full and honest account would probably land them behind bars for years, perhaps for murder.

In Washington last Thursday, the five sisters and fiancée of Robert McCartney followed their meeting with the President by attending a St Patrick's Day party at the home of Ireland's ambassador to the US, Noel Fahey.

By the time they showed up at the sumptuous house in north-west Washington, they had endured several days of being whisked around the capital. There had been meetings on Capitol Hill with senators and congressmen, a gala dinner and then, finally, the meeting in the Oval Office with President Bush. That they had the energy even to show up for the traditional knees-up, where a band played Irish music and the Guinness flowed, was a testament to the determination that has fuelled their campaign.

Mr Bush, they said, had listened carefully to what they had to say and had said he would help them. Other people they had met in Washington had likewise expressed an interest in what they were doing.

Senator John McCain, who calls himself Scots Irish, declared: "Anyone, Irish, American or British who desires and works for the success of peace, freedom and justice must denounce, in the strongest possible terms, not only the cowards who murdered Robert McCartney but the IRA itself and any political organisation that would associate with them."

Gerry Adams was getting the cold shoulder while the sisters were being fêted by his old friends Senators Ted Kennedy and Hillary Clinton. Officially, he was not being shunned. The White House said that Mr Adams - warned not to do any fund-raising during his visit at the risk of having his visa revoked - had not been asked to meet President Bush because no politicians were being invited as a result of the stalled peace process. But the unofficial message was a public rebuke from the Irish American establishment. Mr Adams had to settle for a meeting with Mitchell Reiss, the White House envoy to Northern Ireland.

Mr Adams was, however, well received in most of the places he went during his week-long visit. At a rally of the transport workers' union in New York on Monday, he was loudly cheered. At a breakfast meeting for Friends of Sinn Fein in Washington, he was warmly welcomed. It also emerged that he had met the Irish Prime Minister, Bertie Ahern, for almost an hour on Wednesday to discuss the peace process.

But Mr Adams did little to hide his displeasure. On St Patrick's Day he snarled at reporters who asked him if he was being snubbed, and claimed that the McCartneys were being used: "Let there be no doubt that factions of the media, as well as political opponents of Sinn Fein, have very opportunistically exploited this man's killing."

The six women reject this. Paula McCartney said claims that they were being used by others was nothing more than a "distraction". Their late brother was the only one "behind the scenes". "People have tried to manipulate us but we have been able to identify them," she said. Their appeal to the people of the Short Strand, the Catholic enclave of Belfast where two of the women live, and to the republican community depends on such feisty independence. No high-level political achievement will mean much to the sisters, however, unless they can locate and put the people who killed their brother behind bars.