Angered by the killing of an American soldier by terrorists in Afghanistan, US President Donald Trump let off the first Twitter salvo of 2018 bringing into sharp focus Washington's $33-billion problem of Pakistan and Islamabad's ties to terror and anti-American activities.
Trump's warning also tests the limits of Washington's influence and power to make Islamabad give up its use of terrorists as proxy.
"No more," Trump ended his New Year morning tweet on Pakistan that also took a swipe at his predecessors, Barack Obama and George W. Bush, for "foolishly" aiding Islamabad which thinks of US leaders as "fools".
"They give safe haven to the terrorists we hunt in Afghanistan, with little help," he tweeted, accusing Islamabad of lies and deceit.
On Tuesday, the administration's hawk, Permanent UN Representative Nikki Haley, emphasised Trump's resolve.
"The President is willing to go to great lengths to stop all funding for Pakistan if they continue to harbour and support terrorism," she declared.
If the timing of his 6.12 a.m. tweet on New Year's Day while the country was barely awake after the midnight celebrations seemed a puzzle, the provocation was revealed later when the US commander in Afghanistan, General John Nicholson, announced the death of the soldier in Nangarhar province, which borders Pakistan.
Four other soldiers were injured in the attack.
Trump's "No more" declaration is a restatement of what was already underway -- in August the administration had notified Congress that it was withholding $225 million in military aid to Pakistan.
Yet, as with all Trump's actions, it is a transactional ploy in the style of a businessman and "no more" isn't the final, irrevocable mandate it would appear.
Trump had stepped back once already. In August, he said Pakistan has "much to lose" by harbouring terrorists and his administration announced it was holding back aid.
But in October after Pakistanis got a US citizen released from Haqqani captivity, Trump tweeted: "Starting to develop much better relations with Pakistan and its leaders. I want to thank them for their cooperation on many fronts."
Trump, who is raising troop levels in Afghanistan, is caught between two needs: Preventing terrorist attacks on US personnel, especially from Islamabad's proxies, while keeping the sea-based supply lines to landlocked Afghanistan open.
Pakistan also borders Trump's great foe, Iran, which he took on in his very next tweet.
Therefore, Islamabad also has bargaining chips and it will come down to how much each side can give up to keep the uneasy relationship going.
In one of the first responses to Trump's tweet, Islamabad banned Lashkar-e-Taiba (LeT) leader Hafiz Saeed's charitable organisation, Jamaat-ud-Dawa, from collecting donations. But the mastermind of the 2008 terrorist attacks in Mumbai continues to operate freely in Pakistan in defiance of the US, which has put a $10 million bounty on him.
The other part of the Trump strategy brings India into play. He has called for a greater role for India in Afghanistan -- but mostly as an aid-giver. Ironically, India has been able to fulfil this role only through the Iranian Chabahar Port.
The greater part of the regional role Trump sees for India is in the Indo-Pacific region as a counterweight to China.
That brings China into both the aid and strategic equations with Pakistan that also faces off India, with which Beijing's relationships are often tense.
China is emerging as the main economic power in Pakistan through aid, loans and investments.
Pakistan is the keystone of Beijing's ambitious One Belt, One Road (OBOR) plan to build a link all the way to Europe. A part of that is the China-Pakistan Economic Corridor (CPEC) which aims to grow Pakistan's economy through several billion dollars of investments and aid in several sectors, ranging from infrastructure and irrigation to industry and agriculture.
To that extent, Pakistan is becoming less dependent on the US. But mostly the US aid has been mostly unconditional, geared to the military and giving access to technologically advanced armaments.
In contrast, China's aid comes at a future cost as a lot of it is in the form of loans and investments.
The OBOR and CPEC require protection from terrorists and stability. While this would require Pakistan to control terrorism domestically, it could also suit Beijing to divert terrorists' attention to India and to a lesser extent to Afghanistan.
Simultaneously, China is trying to assume a higher profile in Afghanistan, which could benefit Pakistan.
Last month, Foreign Ministers Salahuddin Rabbani of Afghanistan, Khawaja Asif of Pakistan and Wang Yi of China met in Beijing. Afghanistan's Defence Minister Tariq Shah Bahrami also went to Beijing.