Rod J. Rosenstein may have the second most difficult job in Washington, behind Robert S. Mueller III. The deputy attorney general is the public face and overseer of the extremely contentious Mueller investigation, all while dealing with the whims and apparent attempts to politicize it by his boss, President Trump, who also happens to be a central figure in the probe.

But is he indulging Trump's and his allies' conspiracy theories too much?

That long-simmering fear started to boil Sunday night. Hours after Trump tweeted Sunday that he would “officially” call on the Justice Department to investigate whether the FBI infiltrated his campaign for political purposes — based on little more than apparent speculation — Rosenstein gave in somewhat. The Justice Department announced it would expand an existing inspector general inquiry to answer that question.

“If anyone did infiltrate or surveil participants in a presidential campaign for inappropriate purposes, we need to know about it and take appropriate action,” Rosenstein said in a statement.

The announcement was rather remarkable. Some saw it as deft maneuvering from Rosenstein. It's certainly a compromise, and it doesn't give Trump exactly what he wanted. It could effectively run out the clock by burying the matter in a lengthy inspector general's probe. And it could also avert a potential constitutional crisis that could arise out of Trump ordering DOJ to do something and DOJ declining.

Deputy Attorney General Rod J. Rosenstein has been the target of President Trump's ire for months. Here's a look back at their history. (Jenny Starrs, Monica Akhtar/The Washington Post)

But the concession does risk further politicization of Justice Department business and also unavoidably lends credence to Trump's allegations. Trump can now credibly say the Justice Department is looking into political bias in the Russia investigation, which risks furthering his goal of undermining the entire investigation. And Rosenstein basically handed him that PR win without much actual evidence.

Some questioned the decision.

But this is merely the latest episode in which Rosenstein has apparently tried to mollify Trump and other critics of the investigation — at the risk of “surrendering important DOJ equities,” in the words of former Obama Justice Department spokesman Matthew Miller.

From the very moment the Mueller investigation began, Rosenstein has taken some questionable actions that seemed to hand Trump talking points:

That last one is key. It's admittedly on a much smaller scale than these other ones, but Rosenstein must have known how his statement would be deliberately misconstrued, given that a similar statement in the intelligence community's report on Russian interference has been repeatedly butchered for political purposes. It was almost like he was offering it as an olive branch to Trump, and in that way it fits with everything else on the list.

Rosenstein certainly has his reasons. Trump has repeatedly derided him and reportedly considered firing him. That 44 percent of Americans (read: Republican voters) think the Russia investigation is a “witch hunt” must certainly weigh on these decisions. And it seems possible Rosenstein is just trying to buy some time.

But that time comes at an expense.

“My worry is that each time he does it, he just turns up the temperature on the pot he’s sitting in, and we won’t know the water is boiling until it’s too late,” Miller told me. “It is very hard to tell with Rosenstein when he is appeasing Trump because he doesn’t have the backbone to stand up to him, and when he is doing it because he is trying to buy space for Mueller to complete his work.”

Rosenstein's motives may be justifiable, and he may be being strategic — to the point where these decisions may one day be vindicated. Perhaps he knows approximately what will come from the Mueller investigation, and he knows how important it is to hold off Trump and his congressional allies for just a couple more months.

Rosenstein offered a defiant message to those same congressional allies a few weeks ago — “I think they should understand by now that the Department of Justice is not going to be extorted” — but the reality of his actions has been much more nuanced.