Tolerance: permissiveness; a disposition to allow freedom of choice and behavior, a willingness to recognize and respect the beliefs or practices of others (wordnetweb.princeton.edu/perl/webwn)
Tolerance is allowing the practices of others to continue without interfering. But no one can be tolerant... not of everything. Tolerance is saying that I don't think homosexuality is ok, but sure, you guys can go have sex. Tolerance is saying that you know her unborn child is as much a child as a your two year old son, but if she wants to abuse or kill her children, she can go ahead, you won't stop her. Tolerance is saying that even if I'm gay, if you want to preserve the tradition and idea behind marriage, I won't threaten that ideal, belief or practice... I won't interfere. That's your practice, your belief.
In the end, tolerance only works till someone crosses a line. Buddha, Ghandi, or even the most neutral of people, if faced with someone who practices child sacrifice and is going to do so in front of them, would probably interfere. Non-violently, maybe, but he wouldn't stand by and let them kill kids. That's intolerance, but it's not wrong. Tolerance is allowing anyone to follow their behavioral choices, practices and beliefs regardless of what those entail. Intolerance can be in respect too. Intolerance is simply not standing for something, not allowing it. Enemies can have respect for each other and still strive to kill each other. Tolerance and intolerance does not have to be about respect, it's about actually letting anyone do whatever they want to do. Intolerance is drawing the line somewhere. Preserving a value system, whether it's protecting the innocent or killing them, is intolerance. The US entered a war that they were neutral in, unwilling to interfere, because the Japanese crossed a line. That was intolerance. Ghandi held non-violent protests to interfere, resist, and stop British imposed taxes. That was textbook intolerance. Non-violent intolerance, but there's no masking the fact that he was making a stand to protest something that his value system identified as wrong and something that he couldn't stand by and watch.
Tolerance means there's nothing at stake you believe in enough to make a stand for. It means there's nothing anyone can do that crosses enough lines to deserve interference on your part. Teaching tolerance is ignorant. Teaching the next generation not to make a stand for what they believe in is teaching them to forget lessons like Ghandi's, or Emiliano Zapata's, or Nestor Makhno's, or Buenaventura Durruti's, or Booker T. Washington's, or Martin Luther King Jr's or before that, Harriet Beecher Stowe's or, on the flipside, John Calhoun's and Henry Clay's. World history is filled with the lessons men teach in making a stand, whether with a band of comrades or left alone, for something they know is right, and against something they cannot ignore. Teaching the next generation to form values so that they know which points are the right points to make an intolerant stand against, say, sex trafficking at the superbowl or abuse and rape, is a teaching them to know the difference between appropriate tolerance and appropriate intolerance.
People often use tolerance as a mechanism for the presence of peace. If there is no one willing to make a stand or interfere with any other practice, say Americans won't interfere with Amazonian tribal cannibalism, or the british won't interfere with child trafficking in the Middle east and in Africa, or on the individual level, americans witness crime, rape, murder, and child abuse, and don't interfere, but just let it all happen, that's tolerance. And as long as no one dissents or makes a stand, it's a globally peaceful world. As long as there is no values that anyone holds, as long as there's not a single frame of reference one can form for morality, you have tolerance and, if global tolerance, peace. No one can protest that there won't be crime in a better world, because historically, when people can do whatever they want unimpeded, they always do. And police aren't an exception to the tolerance rule. They can't interfere, because that's intolerant, so they must let everyone go.
This isn't even a radical, hypothetical conclusion. These are radical examples, so even the most 'tolerant' of you will feel something, but this is what tolerance is. Not what it can lead to. Tolerance is not interfering, it's accepting and allowing anything. To pick and choose what's appropriate to allow, that's intolerance. Again, teaching the next generation to react to everyone in tolerance, is teaching them to accept everything, never to form opinions or conclusions for themselves, and to have no real value system at all. History falls on the shoulders of those who make stands for their values, and we will be shamed for letting our generation grow up with nothing to show for itself.