When it was Rex Tillerson’s turn to face a confirmation hearing he found himself jousting with Sen. Marco Rubio, R-Florida over whether or not Russian President Vladimir Putin is a war criminal and a human rights abuser. Tillerson, who has been nominated to be soon to be President Donald Trump’s secretary of state, was reluctant to say that Putin was those things categorically. Rubio was unsatisfied with those answers and suggested that he might vote against him. If every other Democrat also votes against, the Senate Foreign Relations Committee will have voted not to recommend confirmation.

Putin is without a doubt a war criminal and a human rights abuser. His air force drops bombs on Syrian civilians, killing them without discrimination. He regularly has his political opponents killed Mafioso style. However, Tillerson may not want to say so publicly in advance of the formulation of a Russia policy by the incoming Trump administration.

Rubio knows what he is doing. He suspects that both Trump and Tillerson are too friendly toward Putin to suit America’s interests and common decency. He would like to prod both into a direction of more opposition to the Russian tyrant. During the same press conference during which he lambasted a CNN reporter for the fake Buzzfeed news, Trump suggested that it is better to have good relations with Russia than not, but admitted that he could foresee not being friendly with Putin.

Rubio needs to be careful. If he sinks Tillerson, Trump will simply nominate someone like him, and the young senator from Florida will have earned the soon to be president’s undying enmity. Rubio has to use his own art of the deal and extract some kind of concession from Trump in return for getting behind Tillerson, perhaps a commitment to take a harder line on Putin than the president-elect has hitherto been willing to make.

Trump may not like being boxed in by a former opponent for the presidency for whom he has expressed contempt. But he also understands that in some cases he will have to give in on certain things to get what he wants.