such an inchoate mess that it increasingly seems as though no deal will get done at all. " data-share-img="" data-share="twitter,facebook,linkedin,reddit,google,mail" data-share-count="false">

Listen to anybody on Capitol Hill, and they’ll tell you that the debt ceiling debate is turning into a complete disaster, with the Republican rank and file such an inchoate mess that it increasingly seems as though no deal will get done at all. Look at the Treasury market, however, where the 10-year bond currently yields something less than 3%, and it looks decidedly sanguine; short-term debt maturing shortly after the drop-dead date of August 2 is similarly unaffected by the news from Washington.

Megan McCardle thinks this shows a “giant disconnect” between Wall Street and Washington — things which Wall Street thinks are easy turn out in reality to be extremely hard, and things which any Wall Streeter would just do as a matter of course can be de facto impossible when political posturing starts getting in the way.

I’m not sure the disconnect is all that huge, for a couple of reasons. For one thing, US default risk is impossible to hedge. US default is an end-of-the-world event, and markets by their nature can’t price such things. Conceptually, there’s no point in buying something which pays off if the world ends, since the world will have ended at that point, and in any case your counterparty won’t be able to make good on the contract.

On top of that, remember that we already hit the debt ceiling on May 16 — two months ago. Since then, the amount of outstanding Treasury securities — a number which normally rises steadily — has been stuck at $14.3 trillion. The fact that supply of Treasuries has been artificially constrained by the debt ceiling has surely, at the margin, helped to support prices.

And more generally there are still a lot of individuals and institutions who want to buy Treasury bonds. That number might have been falling in recent weeks, but it’s still large. The U.S. is not facing the kind of emergency we’re seeing in the eurozone, where countries want to borrow money but no one’s willing to lend to them. If Treasury asks to borrow money from the markets, the markets will always lend it money; the only question is how much interest they will charge.

This is where McArdle goes awry, incidentally: she’s worried that any new debt issued after August 2 won’t be able to find buyers if Congress doesn’t raise the debt ceiling. But there will always be buyers, and there will always be buyers at yields very, very close to the secondary-market price for Treasury bonds. Treasury bonds are fungible, and to underscore that fact Treasury could easily just reopen old bond issuances instead of creating new ones. That would ensure that there was no way of telling the difference between bonds issued “legally” and bonds issued after the debt ceiling was breached.

Even if Treasury can still sell bonds, however, that doesn’t mean for a minute that breaching the debt ceiling is something which should be considered possible for the purposes of the current negotiation. Tools like the 14th Amendment or even crazier loopholes like coin seignorage would be signs of the utter failure of the US political system and civil society. And that alone could mean the loss of America’s status as a safe haven and a reserve currency. The present value of such a loss? Much bigger than $2 trillion. (Coin seignorage, if you’re wondering, is the right that Treasury has to mint a couple of one-ounce, $1 trillion coins and deposit those coins in its account at the New York Fed. It could then withdraw cash from that Fed account to make all the payments it wanted.)

This is one reason why I worry a lot about clever ideas like Mitch McConnell’s plan to get the debt limit raised through a novel use of the Presidential veto — or, for that matter, Matt Yglesias’s even cleverer plan for Democrats to game the McConnell scheme. McConnell is one of Congress’ foremost tacticians, but cunning tactics on either side of the aisle are the last thing that anybody needs right now.

When Bob Rubin did a nifty sidestep around Congress and magicked Mexico’s bailout billions from some dusty account no one knew about, he was playing a dangerous game. When Hank Paulson and Ben Bernanke stretched the limits of their powers almost beyond the legal breaking point during the financial crisis, their actions were understandable but also set yet another precedent. And so now, when there’s no immediate emergency at all, people are looking to the executive branch to find a way to do the right thing, and thereby giving Congress implicit permission to play out and generally behave with all the maturity of a group of rampaging destructive adolescents.

The base-case scenario is, still, that the debt ceiling will be raised, somehow. But already an enormous amount of damage has been done: the US Congress has demonstrated clearly that it can’t be trusted to govern the country in a responsible manner. And the tail-risk implications for markets are huge. Think of the speed with which the Egyptian government collapsed earlier this year, or the incredible downward velocity of News Corporation right now. When you build up large stocks of mistrust and ill will, nothing can happen for a very long time. But when something does happen, it’s much quicker and much worse than anybody could have anticipated. The markets might not be punishing the US government at the moment. But the mistrust and ill will is there, believe me. And when it appears, it will appear with a vengeance.