During Donald Trump and Vladimir Putin’s joint press conference following the summit, the Russian president proposed that special counsel Robert Mueller use the 1999 US–Russia Mutual Legal Assistance Treaty to make a formal request for Russian investigative assistance in the charges against 12 current Russian intelligence officers for interference in the 2016 US elections.

Specifically, he said that if a formal request was approved, Mueller’s team could even be present for any interviews conducted by Russian law enforcement. But he also attached a condition that Russia be allowed to investigate and interrogate American law enforcement and intelligence officials in the US—presumably on the election interference claim and unrelated politically based complaints that Russia has against a British citizen and former US officials.

Trump, apparently without any consultation with his law enforcement or security experts, declared this to be ‘an incredible offer’. It’s not.

I agree with many who have said that it wasn’t really a serious offer by Putin, but rather was political posturing or, perhaps, messaging. However, assuming for a moment that it was in any way a serious offer, it certainly did not merit serious consideration.

Mutual legal assistance treaties (MLATs) can be a valuable law-enforcement tool for formally requesting and receiving evidence and other investigative assistance between countries. Yet, particularly in the digital age, they are often an imperfect tool, requiring compliance with elaborate formal procedures, including the packaging of evidence justifying the request. It can take many months or over a year to actually produce any evidence. And that’s in the best of cases, when the interests of the two countries are aligned, and there’s trust between them. There’s little current alignment or trust with Russia.

In my experience as a longtime federal cybercrime prosecutor and later diplomat, the MLAT process on cybercrime cases with Russia was extremely difficult and, with few exceptions, largely ineffectual. Requests would often go completely unanswered. Sometimes they would become the platform for seemingly endless requests for more information, or the subjects of the requests would simply disappear. That led to speculation that the subjects of the requests were acting as proxies of the government, or at least were acting with some official or unofficial protection.

Many believed that the most talented hackers had been recruited by the government once they had been identified by US or other law enforcement agencies. The long list of unfulfilled MLAT requests from both sides became a regular issue in bilateral discussions, including the high-level bilateral cybersecurity discussions I helped lead with Russia—back when we had those dialogues before they were suspended after Russia’s incursion into Ukraine.

Partly in response to the lack of any meaningful cooperation in a number of cybercrime cases originating from Russia, the US began indicting Russia-based hackers and arresting them in third countries. That drew repeated protests from Russia, which wanted all evidence sent to Moscow so that any Russian defendants could be charged and prosecuted there—though given their track record, there was little reason to believe they would take action.

Of course, in many ways, this is all beside the point because, in this case, members of the Russian intelligence service acting on behalf of the Russian government are the defendants. In my many years as a prosecutor, the number of cases I jointly investigated with the defendants was, not surprisingly, zero.

Even if the MLAT process with Russia were a model of cooperation and efficiency, it makes little sense to ask the Russian government to investigate itself and hope that would yield any useful information. Even if US investigators were allowed to be present when Russian officials questioned their colleagues, it’s hard to believe it would be anything other than an elaborate stage play.

Moreover, it is clear from the indictment that Mueller already has a wealth of information and evidence and doesn’t need to engage in this process for the unlikely prospect of getting more. While the US would gain nothing, the Russians would gain legitimacy and shift blame—seeming to partner with the Americans to find the ‘real’ perpetrators while declaring their innocence (a strange echo of the O.J. Simpson defence).

Indeed, this is Moscow’s attempted standard operating procedure in a host of recent events in which it has been implicated. The Russians offered to do a joint investigation with the Dutch into the shooting down of MH17, which was refused. They offered to do a joint investigation with the United Kingdom into the Salisbury poisonings, which was also refused.

It is also important here that the indictment charges not only state actors but also state intelligence operatives and lays bare their actions and identities with striking precision. It’s a sure bet that the Russian government wants to know how its tradecraft and operatives were so thoroughly exposed. A joint investigation, or use of an MLAT that may require disclosure of the evidence underlying the indictment, would give Russian intelligence insight into the investigative sources and methods used to uncover their operatives and activities.

Putin made an additional play for this kind of information during the press conference when he suggested that ‘any specific material [related to election interference] if such things arise, we are ready to analyse together. For instance, we can analyse them through the joint working group on cybersecurity, the establishment of which we discussed during our previous contacts’.

Whatever the fate of some future possible working group, such a platform is not an appropriate place for sharing investigative information and it would be a mistake to do so. Although the indictment goes into great detail, the evidence and methods for discovering Russian intelligence activity have not been released and disclosure would only aid Moscow in concealing future activities. None of this inures to the benefit of the United States or its future ability to repel and respond to future attacks.

Finally, there’s another reason to reject this ‘incredible offer’ out of hand. Putin’s pre-condition of a quid pro quo is unacceptable. His request, expressly involving long-time Putin foe William Browder, and now apparently including former US ambassador to Russia Michael McFaul, appears to be based on conjecture and politically motivated. Indeed, Interpol has consistently refused to issue ‘red’ notices (which allow international arrests of fugitives) for Browder because it has found that his prosecution by Russia is a political matter.

MLAT requests are evaluated on their individual merits, requiring evidence of an actual crime that would be a crime in both Russia and the US. The MLAT with Russia excludes political crimes. There’s no reason that the US should subject American citizens or others to a politically motivated Russian investigation. In addition, subjecting a former US ambassador to politically motivated questioning by the country in which he served creates a dangerous precedent and rightfully drew bipartisan scorn. It is amazing that the White House said they were still considering such an arrangement. Thankfully, they finally turned it down, though after far more consideration than it deserved.