Indonesian President Susilo Bambang Yudhoyono was a clear winner in his country's April 9 parliamentary elections.

Indications are that Susilo's Democrat Party increased its 7.5 per cent support from the 2004 elections to approximately 20 per cent. Whether his party clears the legal 20 per cent threshold of seats required to name its own presidential candidate does not practically matter; either way, Susilo will need to form a governing coalition. The most important part of the coalition will be his choice of a vice-presidential running mate.

The other major outcome of the election is the setback dealt to Islamist parties. Partai Keadilan Sejahtera (PKS), the ideology's standard-bearer, failed to improve substantially from its 2004 share. Throughout the last year, PKS held firmly to a goal of garnering 20 per cent of the vote. That was probably never on the cards. But they outwitted themselves on the 15 per cent they might have reasonably hoped for.

To expand their base, PKS sought to appeal to Indonesian nationalism and play down their Islamism. They portrayed themselves as members of the political elite, ingratiated themselves with Susilo at every opportunity, and floated coalition balloons with each of the mainstream parties.

Their campaign failed. Indonesians went with more trusted sources: a president who has largely led the country in the right direction, and older parties with which voters are more comfortable.

At the same time, PKS failed to pick up defections from the other Islamist parties. Two of these parties went below the 2.5 per cent threshold for representation in Parliament. The fourth, the Partai Pengusaha dan Pekerja (PPP) of the Suharto era, continued its long decline, hovering around five per cent of the vote.

It is unclear where all these voters went -- although it seems certain they did not go to PKS. Maybe they were as confused by PKS's appeals to non-sectarian nationalism as everyone else.

No political victories are permanent. In 1999, PKS failed to make the threshold necessary to contest the 2004 elections. It changed its name to qualify and emerged in 2004 with 45 seats and three cabinet posts.

They turned the name change to their advantage, using it to obscure their previously more explicit ideological agenda. They had been running from those roots ever since to good, steady effect - until now. Their loss will exacerbate infighting and likely lead them to rely more on their missionary political work.

However, there is one other possibility that could save PKS from its defeat and pending turmoil. The Indonesian electorate's attention now turns to the nominating process for president. Only nine of the 38 parties contesting the parliamentary elections qualified for representation, and only a handful of them will field presidential candidates.

The system will force them into multiparty coalitions, each representing at least 20 per cent of the seats in the People's Representative Council (DPR). Even if Susilo's Democrat Party ends up with the 20 per cent of seats necessary to nominate him without a coalition, he will still require a coalition of supporting parties to compete effectively in July.

Susilo would seem to be in the driver's seat for the coming presidential election. His party finished far ahead of the others, virtually tripling its 2004 total, and the big parties - Megawati Sukarnoputri's Partai Demokrasi Indonesia Perjuangan (PDI-P) and Golkar - lost votes.

But the situation is complicated. If PDI-P and Golkar - the second and third-place finishers - come together, Susilo would be left with few choices for a vice-presidential partner. He could resurrect his partnership with Golkar, either by patching up political affairs with his current vice-president or running with another Golkar candidate (the sultan of Yogyakarta, for example). He could reach out to Partai Kebangkitan Bangsa and Partai Amanat Nasional, but given their declining fortunes, that is unlikely.

The other prospect for vice-president is Hidayat Nur Wahid, the former president of PKS and the speaker of the joint assembly and holder of three degrees from University of Medina in Saudi Arabia. Eight per cent may be far below what PKS had hoped for, but it did hold its own, and it has strong organisational capacity. Securing a spot a heartbeat away from the presidency would more than salvage their poor performance in the parliamentary elections.

Susilo has clearly done some things of mutual importance to Indonesia and the United States. On his watch, Indonesia has prosecuted the war on terrorism quite effectively: Indonesia is now going on its fourth year without a major terrorist attack.

Under Susilo's leadership, Indonesia is reasserting itself in East Asian politics, and speaking aloud about the importance of values in its foreign policy. On this basis, the Obama administration is rightly committed to taking the US-Indonesia relationship to a new level of partnership.

Susilo's election victory should give him the confidence he needs to develop and assert his own vision for Indonesia. With his choice of a vice-presidential candidate, he will tell the world something about that vision.

There are many factors to consider in his choice - political calculations top among them - but if he cares about establishing a deeper, mutually beneficial relationship with the US, he will consider the way his choice will be received outside Indonesia.

Throwing PKS a lifeline by giving them the vice-presidency will effectively kill any effort to take the US-Indonesia relationship to the next level.

Walter Lohman is senior research fellow for Southeast Asia in the Asian Studies Center at the Heritage Foundation.