Pakistan on Wednesday arrested the mastermind behind the 2008 Mumbai terror attacks, Hafiz Saeed, whose prosecution has long been sought by New Delhi and Washington over the ghastly attacks in India's financial capital.
In Washington, US President Donald Trump welcomed the arrest. In a tweet on Wednesday morning, Trump wrote, "After a 10-year search, the so-called 'mastermind' of the Mumbai terror attacks has been arrested in Pakistan. Great pressure has been exerted over the last two years to find him!"
The US State Department also welcomed the arrest saying, "The arrest of LeT leader Hafiz Saeed is a positive step. A full and expeditious prosecution for his involvement in numerous acts of terror, such as the Mumbai attacks that killed 166 people, including six Americans is necessary. The victims of the terrorist attacks deserve justice."
Contrary to Trump's characterisation of a prolonged 'search', Pakistani authorities have been aware of Saeed's whereabouts for years, critics have argued.
Analysts in Washington see the detention as major cosmetic move ahead of Pakistan Prime Minister Imran Khan's maiden official visit to the United States and said, "clearly, much is being done to put a happy face on Imran Khan's visit to Washington DC."
"I think the arrest of Hafiz Saeed is purely cosmetic because there is no historical basis to conclude otherwise. Washington probably believes as I do, but places other issues like Pakistan's potential positive role in the Afghan peace process as a higher priority, an assumption that, in my opinion, is mistaken," said Lawrence Sellin, a retired US Army Reserve colonel, Iraq, and an Afghanistan veteran.
Trump's South Asia policy was seen as radical two years ago for its tough stance on Pakistan, but with Imran Khan's visit to Washington from July 21 to 23, the policy seems to have made a sudden U-turn on some key aspects.
The changed South Asia policy of the Trump administration now has a welcoming bouquet of positives for Pakistan. Some of the positives that moved within weeks before the big Trump-Khan meet - Hafiz Saeed's arrest, a four-party joint statement on Afghan peace process being released, the Balochistan Liberation Army (BLA) being suddenly designated a terrorist organisation and the International Monetary Fund (IMF) loan for USD 6 billion being approved.
"I think this arrest should be seen in the same context as a number of other recent notable developments: Pakistan calling for India to resume dialogue, Pakistan arresting dozens of militants, and even Pakistan announcing it would be gifting a portrait of Donald Trump to the US President," said Michael Kugelman, deputy director of the Asia Program at the US-based Wilson's Center.
Pakistan is leading a charm offensive in advance of Khan's visit to the US, in the hope that US officials will be receptive to a number of Pakistani pitches and asks," he said.
Pakistan faces the threat of international financial sanctions over lax controls on financial close that could go to terrorists. Islamabad needs to show action in the next few weeks to prevent itself from being blacklisted that would restrict its access to the international banking system.
Pulitzer Prize-winner journalist and former New York Times reporter Pir Zubair Shah told ANI about Pakistan facing its worst economic crisis.
"The news of Hafiz Saeed's arrest is clearly an effort by Pakistan to show to the US that it is now serious in combating terrorism and is willing to listen to the US and on the Financial Action Task Force (FATF) demands," Shah said.
Meanwhile, Taj Ayubi, an international affairs advisor to former Afghan president Hamid Karzai and someone who played an active role in the Afghan resistance against the Soviets, also told ANI, "Pakistan is financially stapled and is almost on the verge of an economic collapse. It is desperately hoping it can get US assistance, maybe the World Bank or other financial institution. For the Khan government, this trip here to the US will give the crippled economy a push where Saudi Arabia and China would help Pakistan."
Islamabad has announced a raft of arrests, seizures of assets and other actions over the past few months against militants, saying it was taking a "proactive approach and that our territory cannot be used against anyone."
Imran Khan's White House meeting is expected by the experts to be dominated by Afghanistan, where Pakistan is playing a key role in supporting talks between the US and the Taliban, another jihadist group that Islamabad is accused of supporting.
But Pakistan's relation with India is also expected to be discussed during the meet, with the two countries coming close to war earlier this year.
A source within the Indian government sounded a note of scepticism about Saeed's arrest.
'This is not the first time that Hafiz Saeed has been arrested or detained. This drama has taken place at least eight times since 2001. The question is whether this time it would be more than a cosmetic exercise and whether Saeed will be tried and sentenced for his terrorist activities," the official told ANI speaking on the condition of anonymity.
The official said that Pakistan's sincerity to take action against terrorism will be judged on the basis of their ability to demonstrate verifiable, credible and irreversible actions against terrorists and to disrupt and dismantle terror groups operating from their soil.
"We hope that this time Hafiz Saeed will genuinely be brought to justice," the official said.
The Trump-Khan meeting will likely to be relatively short and experts do not anticipate many splashy announcements or new deals. Experts say that this visit could be mere optics with nothing of substance on the table or maybe even a pie in the sky.
It is a major diplomatic victory for Imran Khan - just being invited to Washington DC to meet Trump.