This is simply not true. Most regional traditions of Buddhism do not allow for the use of violence with justification and, regardless, the Buddhist suttas do not provide any such justification.
At least in Sri Lanka, Myanmar, and Thailand, modern Buddhism adopted a number of innovations and interpretations from the Buddhist revivalist movement lead by Anagarika Dharmapala in Sri Lanka back under colonial rule, and all use the Upayakaushalya Sutra to justify their violence as for the "greater good".
When discussing religion, it’s important to not mix up three rather different things:
1. The teaching itself
2. The clerical institution, often fused with and distorted by state power
3. The practice as understood and lived by ordinary people
I disagree. It is always 2 and 3 that sets the tone of a religion because humans have a way of corrupting everything we touch.
1 always remains "highbrow" and isolated from the stresses of 2 and 3; and it's 2 and 3 that set the tone of a religion.
That's human problem, not the teaching's problem. Some monks managed to behave badly even during the times of the Buddha.
The problem of the discussion here is that some participants are claiming that Buddhism is not anti-violence which is like going around claiming that Christianity/Islam is not anti-polytheism.