Sept. 10, 2012 -- "Gaps" in President Obama's leadership contributed to the collapse of a "grand bargain" on spending and debt last year, with the president failing to cultivate congressional relationships that may have helped him break through Republican opposition, author Bob Woodward told ABC News' Diane Sawyer.

Woodward's reporting in his new book, "The Price of Politics," reveals a president whom he said lacked the "stamina" in turning personal relationships with congressional leaders into action the way some of his predecessors have done.

"President Clinton, President Reagan. And if you look at them, you can criticize them for lots of things. They by and large worked their will," Woodward told Sawyer."On this, President Obama did not."

"Now, some people are going to say he was fighting a brick wall, the Republicans in the House and the Republicans in Congress. Others will say it's the president's job to figure out how to tear down that brick wall. In this case, he did not."

Tune in to "World News with Diane Sawyer" and "Nightline" on Monday September 10, 2012 to see Diane Sawyer's exclusive interview with Bob Woodward

Asked if Obama simply wasn't ready for the job of being president, Woodward responded:

"I am not ducking this. I am weighing evidence, and there's evidence that he got on top of a lot of things, he did a lot of things. And there's evidence that there are gaps," he said. "He did not fix this."

Woodward places particular blame for the failure to reach a deal with Obama, writing that the seeds of discord were planted early in his administration. He displayed "two sides" of his personality in early meetings with congressional leaders, Woodward said.

"There's this divided-man quality to President Obama always. Initially he meets with the congressional leaders, he says you know, 'We're going to be accommodating, we're going to listen, we're going to talk, we're going to compromise," Woodward said.

"But then they -- Republicans ask some questions and challenge him a little bit and he says, 'Look I won. I'm in charge here,' " Woodward continued. "And the Republicans feel totally isolated and ostracized. And this was the beginning of a war."

Last summer's debate over the debt ceiling was an intense period for the Obama presidency -- and a perilous one for the nation. One White House aide described it as the economic equivalent of the Cuban Missile Crisis; in an interview with Woodward, Obama himself compared the tension during this timeframe with his decision to strike Osama bin Laden's compound.

"It's so serious that they couldn't tell the world how bad it was at the time," Woodward said.

But with furious negotiations taking place at several levels, Obama had few key personal relationships to draw on among members of either party.

With a sense, according to Woodward, that "no one was running Washington," even Democrats were left grumbling about the president's lack of leadership. And Republicans proved unwilling to bend on the key question of tax revenue.

Obama is portrayed as having a distrust of Republicans in Congress. But he came closer to a breakthrough deal over spending and debt with House Speaker John Boehner than many observers thought possible.

"If you're dealing with an opponent, you have to sit down and find a way to talk," Woodward said. "They had the merlot-and-Nicorettes meeting, the president and John Boehner, and at least initially made some progress. You have to stick with that. You know there's one quality a president needs -- it's stamina."

Republicans shoulder a share of the blame too, in Woodward's telling. He depicts Boehner's top deputy, House Majority Leader Eric Cantor, at times working against Boehner, reflecting the strong Tea Party sentiments in the Republican conference.

"I also make the point that Speaker Boehner was responsible. He never found a way to go to Eric Cantor and say, and have that kind of conversation of a lifetime and say, 'Eric you're the deputy, you're the majority leader. I'm the boss. It's you and me. We've got to work together as a team.' "

After the "grand bargain" deal fell apart, congressional leaders pieced together a short-term spending deal to avoid an unprecedented default that could have triggered a worldwide financial crisis.

But they did it without Obama, and over some of his explicit objections, leaving the president angered, Woodward said.

"The president was moaning, groaning, whining, demanding, threatening, and desperate. And wow," Woodward said. "I asked the president about this and he said, 'Well, you know, anyone who knows me, I don't moan and groan and get desperate. But he acknowledges he was very angry."

Woodward pushed back at the notion that his book will be used by Republican presidential nominee Mitt Romney and other political foes to make the point that Obama was in over his head. His book, he told Sawyer, is a "legal wiretap," not an attempt to assign blame for a missed opportunity.

"I am not delivering that ammunition. I am trying to describe what happened … I also make the point that Speaker Boehner was responsible," Woodward said. "He had a partner, a dancing partner. He has the Republicans in on this. … I can't simplify it or make a judgment. What I can do is provide that wiretap."

The book paints a grim portrait for the future, including the next few months.

"The overarching theme here is that we dodged a bullet that could have changed this country forever but we dodged it by deflecting it off to the year 2013 which by the way is only several months away," Woodward told Sawyer.

Click here to purchase an advance copy of Bob Woodward's new book "The Price of Politics" on sale Sept. 11, 2012