Wikipedia has a pretty darn good page on methods of spy recruitment, which I found to be a pleasant surprise. Most people find matters of espionage confusing and frustrating, which is understandable because it’s part of the plan for all well-designed clandestine activities. Some things are more difficult than others, though, and it’s certainly easier to understand how you should go about getting someone to betray their country than it is to pierce the plausible deniability built into every decent covert operation.

Simple greed is the most classic weakness spies exploit to recruit foreign agents, but sex isn’t too far behind. Financial inducements can work in cases where need rather than greed is the motivator. Americans have been able to exploit access to our generally excellent health care system, for example, by making expensive surgeries available for spouses and children. During the Cold War, ideological affinity worked well for the Soviets, but the Russians have moved on to exploiting left-wing disgust with iniquities in American society rather than relying on the theoretical attractiveness of their own. When working spotting promising recruits, disaffection is a major attraction. Someone prominent who is visibly upset with how they’ve been treated is a natural target. Sometimes simple flattery can work with them without the need to cultivate their thirst for revenge. In some cases, naiveté or basic stupidity can be exploited, particularly when the subject doesn’t realize that they’re being recruited at all. In other cases, ex-pats’ lingering prideful loyalty to their homeland can be used to get them to turn on their adopted country. And, of course, there’s the old trusty blackmail.

I wasn’t surprised to see that ex-CIA chief of staff Jeremy Bash was on television yesterday saying that it is quite possible that Paul Manafort was sent to the Trump campaign by the Russians. That had been my first thought ever since I read that Manafort had applied for the job unsolicited and with the promise that he would require no pay. All I knew about Manafort at the time was that he had been a partner with Roger Stone in an epically cynical influence-peddling consulting and lobbying firm during the 1980s. He’d worked for some of the most notorious dictators in the world and had a business model based on his ability to win the votes of the candidates he helped to elect. In other words, if I thought I knew anything about Manafort it was that he, like Roger Stone, lacked any core principles and would do unconscionable things for a buck. He was the opposite of the kind of ideologically committed person who offers to work for free. I knew he either had some angle and a plan to make his money somehow, or he wasn’t acting of his own free will.

My suspicions obviously grew when I learned of his work for pro-Putin Ukrainian politicians and then saw how the platform was changed at the Republican National Convention to soften its support of Ukraine. What almost cinched if for me, though, was when I learned about his close working relationship with Oleg Deripaska, a Russian oligarch who is considered one of Putin’s closest allies and who is not allowed in the United States because of his suspected ties to organized crime. Yesterday, I learned that Manafort offered to give campaign intelligence to Deripaska while he was serving as the head of Trump’s campaign. That would make him the highest and most desirable kind of recruit. Here’s the first item on the Americans’ priority list for recruiting foreign spies, but just reverse it and it works for the Russians, too.

1. The most valuable recruit had regular access to “current political and economic intelligence from the installation in question”. Ideally, the asset would be in the highest-priority country and have access to “the minutes of Politburo meetings” or equally critical military, scientific, or other data. In the case of countries that either dominate countries (e.g., the satellites of the former Soviet Union) or client states of another power, officials of the client country, or of the patron country’s representatives in the client, may be easier to recruit than officials in the home country.

As you can see, they weren’t ambitious enough to even contemplate a recruit who is running a presidential campaign. That kind of access was too much for their imaginations. It was obviously superior to getting the minutes of Politburo meetings. Let’s put it this way: Manafort was volunteering to give Putin his firsthand accounts of the Trump campaign. Why would he do that?

There are theories that he owed Deripaska a large sum of money, and I wouldn’t want to owe a Putin-allied oligarch with major ties to the Russian mafia a large sum of money. There are also theories that he just wanted to monetize his position after the election and perhaps gain some needed leverage to recover some debts of his own. The point is, he was compromised by the Russians from the outset, which is clear now that he’s facing charges on things that predate taking the job with Trump. He did a cold walk-in to the Trump campaign, asking for no pay, and was promoted to the top within weeks.

Whether it was greed, need, or blackmail, it seems likely to me that Manafort was guided in his actions.

Michael Flynn, however, is more in the classic mode of the disaffected recruit. Canned by the Obama administration, he was badly wounded. That he would be approached by Russians and invited to sit at a head table with Putin is not surprising. That he was given large contracts and asked to appear on the RT cable news network is exactly how you’d expect a pissed-off former head of the Defense Intelligence Community to be treated by his handlers. That he immediately opened himself up to blackmail is also obvious.

Carter Page fits the mold of the someone for whom naiveté could be exploited with flattery and simple financial inducements.

This all sounds kind of crazy, I know, but it does line up with the facts that we know. Even Trump was enticed with commercial projects and the offer of women during his time in Moscow for the Miss Universe pageant and thereafter. We now know he was seeking a deal on a Moscow Trump Tower right up to the eve of the Iowa Caucuses. We know that Russians found Trump-licensed properties to be friendly places to launder their money and that the Kremlin wanted to keep tabs on who was buying what. There are a host of reasons why the Russians wanted to cultivate relations with Trump, before and during his time as a candidate. They made clear and unmistakable efforts to do so.

More and more evidence is piling up about the degrees to which the Russians were willing to go to help Trump get elected, including starting very successful Facebook groups that organized real-life direct actions.

We have the almost absurd spectacle of Special Counsel Robert Mueller requesting that the White House turn over all documents related to the May meeting the president had with Russian foreign minister, Sergey V. Lavrov, and the then-ambassador to the United States, Sergey I. Kislyak “in the Oval Office the day after James B. Comey, the F.B.I. director, was fired.”

By design, the world of espionage is cloudy and inscrutable. How can one prove someone is spying for a foreign country when they frequently don’t even know they’re doing it? Or when they think they’re spying for a friendly service? Or when plausible exculpatory explanations are built into the plan? It isn’t easy.

Short of hard to come by smoking gun evidence or a direct confession, the best we can usually do is to look at all the connections and incentives and then look at the resulting actions. For Manafort, he acted exactly how a spy would act and not at all how Paul Manafort would act. For Flynn, his recruitment was so open that it isn’t in dispute. His subsequent actions strongly suggest that the recruitment was a success, if for no other reason than his susceptibility to blackmail.

And, Trump?

He sat at the top of this pyramid and lied his face off the entire way about his commercial interests in Russia. That makes it harder to believe that folks like Manafort and Flynn and Page were thrust on him by the Russians, who were clearly more interested in helping him than in tricking or double-crossing him.

The basic outlines here are proven to the point that they’d be adequate for an intelligence report expressing a high degree of confidence in witting cooperation between the Trump campaign and Russian intelligence. But that is not the same thing as proving it beyond a reasonable doubt in a court of law. And it definitely does not yet rise to the level of indisputable truth that would compel a Republican-controlled Congress to impeach the president.

But I’m pretty sure Bob Mueller is getting ready to bring a pretty strong cocktail to the party. If he can get people talking, he might find the proof he needs.