Deciding how to deal with the mass murderers who call themselves the Islamic State is the most pressing policy question now facing the United States. Specifically, the immediate need is to design and speedily implement a plan to work with allied nations – both those of long standing and others temporarily in agreement with us on this danger – to defeat them militarily.

This is a case where broad agreement on the goal does not mean consensus on how to achieve it. In the U.S., two questions must be answered.

 Should we subordinate our legitimate goal of seeing Bashar al-Assad removed from the presidency of Syria so we can better make common cause with his foreign supporters, Iran and Russia?

What role should American troops play, from virtually none up to an actual combat presence of some size.

Both questions resist easy answers, and I will meet what I consider to be my own responsibility to address them next week. But their difficulty is all the more reason for Congress fully to discuss them and, as a part of their duty they often seek to evade, actually vote on what they think appropriate. But we are not getting that response, and the explanation for this failure is one more manifestation of the degree to which the excessive, ideologically rigid partisanship of today’s Republican Party damages the national interest in responsible self-government.

To those who object that this comment is itself unduly partisan, I refer to recent history. Over more than 25 years, from the massacre of hundreds of Marines and the attack on the U.S. Embassy in Lebanon in the ’80s to Saddam’s invasion of Kuwait to the horror of 9/11 to the different but equally grave financial crisis, congressional Democrats responded to the Republican president in each case with a great deal of support and a minimum of partisan criticism. Indeed, the contrast between our response to the Lebanese attacks and the Republican partisan exploitation of the tragic but less damaging murder in Benghazi is so stark that I will also address that farther in the future.

In none of these cases did congressional Democrats refuse to join in taking responsibility for politically difficult decisions, nor did we put all – nor most – of the blame for the problem on the Republican presidents’ actions. Our basic approach was to join in reaching some conclusion on the plan of action that best responded to the challenge, with members having to declare themselves on a recorded vote on whether they supported it or not. There was appropriate expression of partisan differences about the circumstances, but that was always wholly subordinate to the search for a resolution, and in the cases of foreign assaults, there was never any tendency to spend more energy and time faulting the president than on condemning the assailants.

Sadly, today presents a very different picture. Most importantly, the Republicans have engaged in a practice for which they used to criticize people on the left: In cases of foreign troubles, blame America first. We hear much more from the Republicans about Obama’s alleged weakness as a cause for Islamic State’s reign of terror than we do about the acts themselves.

This is an example of inaccurate, irresponsible hyper-partisanship at its worst, factually, and more profoundly, from the standpoint of how our democracy should function. Factually, in addition to the glaring omission in their history of the role played by the worst mistaken policy choice in American history, the Iraq War, the congressional Republicans shamefully accuse Obama of a failure for which they themselves are largely responsible.

In their myth, much of the current problem stems from the president saying he would bomb Syria if it used chemical weapons and then failing to do so. What is wholly, dishonestly omitted from this account is that it was their political cowardice that was responsible.

In an action many critics of unchecked presidential power to commit our military have been advocating for years, Obama asked Congress to authorize the bombing. With Republicans in the lead, both Houses refused – a fact acknowledged by the Republicans senators participating in the first presidential debate. To be clear, Obama did not bomb Syria as he said he wanted to because congressional Republicans blocked him. This has in no way held them back from complaining that his inability to do what they kept him from doing is a major cause of Islamic State’s reign of terror.

Nor was this a one-time demonstration of how to blend political cowardice with hyper-partisan demagoguery. The Republicans have a problem. Their preferred course of action in Syria – and Iraq, Afghanistan and maybe elsewhere – is a significant increase in the deployment of American combat troops – probably amounting in all theaters to a hundred thousand or more.

But many understand that this is not popular with the majority of voters. Their response has two parts.

First, they attack the president for asking only for congressional authority for sustained bombing, with some American ground personnel directing the flights, on the grounds that it is insufficient force. But then, instead of introducing their own alternative to authorize heavy use of combat forces, they simply refuse to vote at all on his request, and hypocritically announce that they cannot put forward their own proposal for what they think is the appropriate level of force until the president sends them a resolution they like better.

Why are the Republicans who have been so denunciatory of Obama’s executive overreach now insisting that they cannot exercise Congress’ constitutional power to declare war – which many of them are calling for – until he gives them permission? The answer is that they want political cover, not constitutional authority. They fear the political consequences of voting for the resolution that embodies their chosen strategy, so instead they choose to attack the president for not doing what they say they want him to do, but conspicuously refrain from voting to tell him to do so. And they do so with more fervor than they bring to the case against Islamic State.

Barney Frank is a retired congressman and the author of landmark legislation. He divides his time between Maine and Massachusetts.

Twitter: BarneyFrank