“IT DOESN'T involve me”, said Donald Trump, after his former campaign chairman, Paul Manafort, was convicted by a court in Virginia on eight counts of financial fraud last month. “This had absolutely nothing to do with the president,” said his spokeswoman, Sarah Sanders, on September 14th, after Mr Manafort unexpectedly pleaded guilty in Washington, DC to two additional charges. As that turned out to be part of a newly-minted cooperation agreement with Robert Mueller, the special counsel, we may soon know whether Mr Trump and Ms Sanders are right.

Assuredly, none of the crimes Mr Manafort has been convicted of or admitted to is directly related to the president. The 69-year-old political operative was convicted last month on eight of a possible 18 charges of tax and bank fraud, and of failing to disclose foreign bank accounts. These related to Mr Manafort’s consulting work on behalf of pro-Russia politicians in Ukraine in the early 2000s, for which he earned around $60m. He also hatched a scheme to borrow $20m fraudulently from American banks. Most of these crimes were committed before he played any part in Mr Trump’s election campaign, and there is no suggestion that the president was involved in any of them.

Mr Manafort was due to stand a second trial, in Washington next week, on seven additional charges. These included money laundering, tax fraud, lying to the justice department, failing to register as a foreign agent and obstructing justice by attempting to influence a potential witness against him. Again, there was nothing in those allegations directly related to Mr Trump. The president has known Mr Manafort for decades. But he is not alleged to have played any part in the crimes Mr Mueller charged him with.

Yet Mr Manafort appears to know something that Mr Mueller, who is investigating possible collusion between Mr Trump’s campaign and Russian election hackers, among other things, wants to know. Hence the cooperation deal the two parties have now struck.

In return for leniency from Mr Mueller, Mr Manafort has committed to assist the government with “any and all” matters. That may involve turning over any documents or other evidence demanded of him, or appearing as a witness for the government, as requested. It will also involve providing an account of “his participation in and knowledge of all criminal activities”.

The seven charges Mr Manafort faced in Washington were as a result reduced to two lesser charges of conspiracy, to which he pleaded guilty. These included financial crimes and witness tampering. He also admitted his guilt on charges of bank fraud that the court in Virginia had failed to reach a verdict on. The other outstanding charges in that trial have been dropped. Yet Mr Manafort has by no means got off lightly.

He agreed to forfeit his wealth. He will hand over to the government four properties, including a condominium in Trump Tower, together worth several million dollars, as well as the contents of four bank accounts and a life insurance policy. More seriously, he has accepted that he faces a total prison sentence of not less than 17.5 years. A life sentence, in other words, for a man of his age. Yet if Mr Manafort provides the government with “substantial assistance in the form of truthful information and, where applicable, testimony,” Mr Mueller may be persuaded to argue for a lesser sentence.

How much help to Mr Mueller can Mr Manafort provide? That is the great question, not least for Mr Manafort’s prospects of leaving prison alive.

He could feasibly be very helpful. Mr Mueller is investigating the Trump campaign’s links to well-connected Russians. And Mr Manafort built a career on his dealings with them. He was communicating with at least one, Oleg Deripaska, an oligarch and ally of Vladimir Putin, while working for Mr Trump. He offered Mr Deripaska, to whom he was either heavily in debt, or heavily in credit, depending whom you believe, “private briefings” about the campaign.

Perhaps more significantly, in June 2016, Mr Manafort attended the meeting in Trump Tower which is the main scrap of evidence in the public domain of collusion between the Trump campaign and Russians. The meeting involved senior members of the campaign—also including Donald Trump Junior and Jared Kushner, Mr Trump's eldest son and son-in-law—and three Russians with Kremlin links, including a lawyer called Natalia Veselnitskaya. The meeting had been arranged by Mr Trump’s son after he was informed that the Russians had dirt to dish on Hillary Clinton.

The Trump administration has denied that and said there is no such dirt. The president has said he knew nothing of the meeting. Mr Manafort can probably tell Mr Mueller whether that is true. No doubt, he already has.

It is hard to imagine the special counsel would have entered into this deal without a pretty good idea of what Mr Manafort had to offer. It might not be a lot. In the worst case for the special counsel, he has forced one of the most senior Trump aides to admit that he is guilty as charged and due many years in prison. In the process Mr Manafort has become the fourth former member of the Trump team to enter into a formal cooperation arrangement with Mr Mueller—the others include Mike Flynn, the former national security adviser, and Mr Manafort’s former partner, Rick Gates. That represents yet another big win for Mr Mueller’s highly productive investigation.

Yet there are also signs that Mr Mueller has been angling for something pretty substantial from Mr Manafort all along. Notwithstanding his Russia connections, Mr Manafort’s crimes fall far outside the special counsel’s main remit: Russian election-hacking and the Trump team’s possible involvement with it. The special counsel might therefore have been expected to hand his case over to regular federal prosecutors—as he did with Mr Trump’s former lawyer, Michael Cohen, who was last month pleaded guilty to eight charges, including tax evasion and lying to a bank. The fact that Mr Mueller chose to keep Mr Manafort to himself could suggest he thinks he has something significant to offer. (Mr Cohen was not offered a deal ahead of his guilty plea. Though, despite having once sworn to “take a bullet” for Mr Trump, Mr Cohen is also reported to be seeking a cooperation agreement with Mr Mueller, in the hope of a lenient sentence.)

A lesser mystery concerns what Mr Manafort has been playing at all this time. The evidence against him was so damning that it always looked as if he would be convicted. With that in mind, he might logically have sought an agreement with Mr Mueller before his case first came to trial, at which point he would have had a stronger negotiating hand. That he did not seek a deal then suggests one of two things, Either Mr Manafort was delusional about his hopes of evading justice. Or he was holding out for a presidential pardon.

Mr Trump’s former lawyer, John Dowd, is reported to have aired the possibility of such a pardon with Mr Manafort’s lawyers last year. Mr Trump loves pardoning people. He also fears Mr Mueller. Yet according to his current chief lawyer, Rudi Giuliani, the president was later dissuaded from considering pardoning any of his aides until after Mr Mueller had completed his investigation. He would otherwise risk providing the special counsel with even more evidence of obstruction of justice than Mr Trump may have provided already.

That has not prevented the president commenting on Mr Manafort’s case. In response to his conviction in Virginia, Mr Trump tweeted: “I feel very badly for Paul Manafort and his wonderful family. “Justice took a 12 year old tax case, among other things, applied tremendous pressure on him and, unlike Michael Cohen, he refused to “break”—make up stories in order to get a “deal.” Such respect for a brave man!”

What does Mr Trump think of brave Mr Manafort now? It shouldn’t take long to find out.