With a tactical move the Republican minority in the Senate has blocked approval of the new head of the Pentagon. They don’t want to rubber stamp their fellow party member, Chuck Hagel. Calculation lies behind this affront, which will have consequences for President Obama and his cabinet.

Harry Reid is angry and fed up with the blocking tactics of the Republicans: “Just when you thought things couldn’t get worse, it gets worse.” Reid, head of the Democratic majority in the Senate, spoke about this as a low point in the history of the Senate while calling attention to the war in Afghanistan and the threatening world outside the United States (North Korea! Iran! Syria!). He hopes very much that nothing happens in the next 10 days to threaten America’s security.

10 days — that’s the least amount of time it will take for the 100 senators to make another decision on secretary of defense nominee Chuck Hagel. Earlier the Republican minority hindered an immediate vote on the nomination. 58 senators voted to end the debate, while 40 Republicans wanted further deliberations. In so doing, the conditions for a filibuster were fulfilled (only a three-fifths majority can break the blockade) — and Valentine’s Day for the president was pretty much ruined.

Texan John Cornyn insisted that the Republicans had not employed a filibuster: They just wanted to know more about Hagel’s income, as well as about those speeches that their fellow party member had given since leaving the Senate. Later, the Grand Old Party would agree to a vote on the ex-senator from Nebraska. This, with the Democrats’ votes, would confirm Hagel, since a simple majority is sufficient. (The Washington Post has summarized the debate over whether or not it was a filibuster.)

Cornyn accused Harry Reid of having forced the Republicans into this vote — and of having used the same tactic that he was now complaining about in 2006 as the then-leader of the Democratic minority. Cornyn is not unjustified: When Reid became aware that he did not have the 60-vote majority, he ordered an immediate vote in order to portray the Republicans as blockers.

While the senators were still accusing one another of placing party interests above the good of the nation, Hagel’s soon-to-be new boss commented in an online chat. The Republicans’ “unprecedented filibuster” of a defense secretary nominee is “unfortunate,” according to an irritated Obama in the “fireside hangout.” The United States has 66,000 soldiers stationed in Afghanistan; he needs a secretary of defense to coordinate with America’s allies.

But why are the Republicans, who otherwise always stage themselves as the defenders of soldiers and veterans, resorting, of all things, to a blockade position on the future head of the Pentagon?

■ Discontent is deep. The longer the American media and political establishment are busy with the candidacy of the Vietnam War veteran, the clearer it has become that many conservatives mistrust Hagel. He made real enemies for himself in Congress and was regarded as a RINO (Republican in name only) who was too critical of Israel and, like Secretary of State John Kerry, a skeptic when it comes to the deployment of America’s military. It was likewise not helpful that Hagel was poorly prepared for his hearing. The calculation: The longer the debate about Hagel lasts, the more Obama’s Middle East policy can be criticized.

■ It creates unity. It is clear that in the Republican camp, the defeat at the polls on Nov. 6 has not yet been digested. Rock solid, they counted on having Mitt Romney move into the White House and being able to win a majority in the Senate. Instead, the Democrats celebrated Obama’s victory and increased their advantage in the Senate. It binds the 45 Republicans together to support a colleague in his wish for more information, according to a conservative advisor to the Washington Post. At the same time, this is a signal to Obama and Harry Reid that the conservatives will not put up with everything. In addition, the Grand Old Party is convinced that the trial of strength is without risk: Hagel has no influential supporters outside of Washington and the majority of voters have no opinion about the 66-year-old — or simply have other worries.

■ It helps their careers. Senators like Lindsey Graham from South Carolina, who will be running for another six-year term in 2014, are using the situation to boost their profiles. Here is an opportunity to show that they are taking advantage of every opportunity to criticize a president who is hated by their voting base. Graham, who fears an even more conservative tea party opponent, is primarily probing the matter of Benghazi — even though Hagel had nothing to do with that.

He will not rubber stamp this candidate until he finds out whether Obama tried to speak to Libya’s government on that Sept. 11. With John McCain, he wants to block CIA chief designee John Brennan until the public — and the 20 million viewers of Fox News — find out who at the CIA changed information for UN Ambassador Susan Rice (details at Politico). On talk shows, she cited a YouTube video that was critical of Islam as the reason for the storming of the consulate in which United States Ambassador Stevens and three other Americans died.

The White House stated that Obama continues to count on Hagel taking over the Pentagon soon. But the controversy will not be without consequences for the political climate in Washington.

■ Hagel will begin from a position of weakness: Highly decorated war veteran, successful businessman, 12 years in the Senate — Hagel’s biography is ideally suited to the new position. But even if he is confirmed at the end of February he will be weakened as the master of over two million soldiers and a budget of billions. Next week the NATO defense ministers will be discussing their Afghanistan strategy in Brussels — ideal for getting to know new colleagues. But now nothing will come of that.

■ The walnuts will have to wait: Instead of Hagel, Leon Panetta will travel to Brussels. The former secretary of defense officially took his leave on Feb. 14 and actually wanted to return to his walnut farm in California. Now the 74-year-old will be doing one last favor for Obama, although he joked after the ceremony, looking at his wife, that it would be wonderful for “Sylvia and I to get the hell out of town at the end of the day.”

■ Obama’s agenda is in danger. In the State of the Union address the president presented ambitious goals. For weapons laws, education and immigration reform Obama needs the support of the Republicans — even if it is only out of self-interest to improve the latter’s image with Latinos. By March 1, a solution to the budget debate must also be found; otherwise automatic cuts will go into effect. And doubts over American politicians’ ability to solve their own problems in order to stimulate the economy will be amplified.

One thing is clear: The seemingly childish quarrels over Chuck Hagel and what is, essentially, a question of personnel will certainly not make future compromises in Washington easier. And the fact that the Republicans let it come to a trial of strength in spite of this inspires little optimism.