The decision on Sunday by Pakistan's major political parties to come together is likely to have far-reaching consequences for the volatile South Asian nation.
By Syed Shoaib Hasan
BBC News, Karachi
The political contours of Pakistan's future are only just emerging
The PPP and PML-N political parties, which won the highest and second highest number of seats respectively in February's elections, have signed an agreement to form the next national government.
The deal comes after weeks of protracted negotiations between the two sides over the last few weeks.
It includes an agreement to restore to office the judges sacked by President Pervez Musharraf when he imposed emergency rule in November 2007.
Initially, it seemed that the differences between the two sides were unbridgeable.
PPP head Asif Ali Zardari - the widower of the party's previous head, Benazir Bhutto - had expressed his willingness to work with President Musharraf.
Mrs Bhutto, and the PPP, made a triumphant return to the centre stage of Pakistani politics last year after seven years on the sidelines.
Mrs Bhutto was subsequently assassinated in a gun and bomb attack in December 2007.
Although her party leadership, including Mr Zardari, said the government held primary responsibility for her death, they did not rule out working with him.
That is at odds with the position of their new coalition partners, the PML-N, headed by former Prime Minister Nawaz Sharif.
Mr Sharif's PML-N has always maintained it does not recognise Mr Musharraf as president and has termed his rule "illegitimate".
Mr Musharraf - then General Musharraf, chief of the country's powerful army - overthrew Mr Sharif and seized power in a bloodless coup in 1999.
The deposed premier, along with his entire family, was subsequently forced into exile.
From that time President Musharraf has seen Mr Sharif as his arch-nemesis.
Since his return as part of internationally brokered political repatriations in 2007, the former prime minster has proven as much.
Mr Zardari, right, is having to agree to many of Mr Sharif's demands
The PML-N's electoral success, which went far beyond pundits' expectations, has enabled Mr Sharif to push his two-point agenda - securing the restoration of sacked judges, and seeing Mr Musharraf out of the presidency - with much greater force.
"The fact is they control the Punjab, and without the Punjab there is no federal government," an analyst points out.
Control of Pakistan's largest province - and its political heartland - has helped propel the PML-N into its enviable position of kingmaker.
The PPP, with the largest overall number of seats in the country, remains the first and strongest claimant to the country's federal throne.
But as the party failed to get a clear majority, it still needs one or more partners to form the government at the centre.
Need for unity
Most analysts' pre-poll predictions gave the highest number of seats to the PPP, followed by the then ruling PML-Q party, allies of President Musharraf.
The "Q" doing well in the election was deemed critical for President Musharraf's survival.
The PML-N and protesters demand that sacked judges are reinstated
But the party was routed in the Punjab, its supposed stronghold, and it ended up as the third largest party by some distance.
"Even if the PPP had won by a majority, Mr Zardari had maintained his party wanted to bring all the major parties on board," another political observer points out.
This was deemed necessary to combat the threat the country faced due to the rise of extremist forces and growing power of the militants in the North West Frontier Province.
But bringing the PML-N on board meant effectively having to accommodate its demands over the judges and their determined stance on the illegitimacy of President Musharraf's rule.
"That was deemed impossible as President Musharraf retained the support of key Western governments, as he was deemed an indispensable ally in the war on terror," offers a former diplomat.
"The international community had made it clear to the PPP leadership that he would have to be kept part of the power equation."
This led to the protracted negotiations in which the PPP leadership tried to convince the PML-N in vain to give up their stance on "the president issue".
Refusal to budge
During this time, President Musharraf's camp tried to bring the PPP together with the PML-Q and the smaller parties in parliament.
But such a scenario was largely unappealing to the former, as it would have meant an openly hostile PML-N in command of the Punjab.
Political unity is seen as a weapon against rising militancy
Meanwhile the kingmakers remained true to their demands and refused to budge on either of the issues.
"They are our central campaign promises," a PML-N leader told the BBC a week ago.
"If we pull back on them, what kind of credibility will we have left with public?"
It was this unequivocal insistence on their part which was the main reason behind 9 March's historic decision.
Insiders say a recent pullback by the international community from its unconditional support of Musharraf was also a factor.
They maintain it remains to be seen whether the coalition will be a lasting one, as it has several ideological barriers to surmount.
But they also say it effectively means the end of President Musharraf's rule in Pakistan.
A parliament, many of whose members have suffered imprisonment and worse during his rule, now waits to decide his fate.
Even if they deem it constitutional to pass the issue on to the restored judges, the outcome is unlikely to be any different.
"President Musharraf can still choose a somewhat honourable exit and resign in coming weeks," says an analyst.
"The alternative is to put himself through the humiliation of impeachment, and even imprisonment for overthrowing Mr Sharif's government."