Do Buddhists have a country or a religion to defend? How is it that militant monks can justify waging war or violence? Is nonviolence not necessarily an absolute value  for the Buddha? What scriptures are  militant monks interpreting to justify war or violence?
Are the militant monks making more or less suffering? Is it right to make more suffering than you have to? Do they have to?
Is there groups that are a threat to Buddhists or the Buddha's teaching?

Do Buddhists have a country to defend?
Do Buddhists have a religion to defend?
One needs to separate the teachings for monks from the teachings for laypeople. For monks, instructing the killing of or actually killing a human being in any circumstance is forbidden. Where as, for laypeople, killing is a training rule.

But sire, what are the noble duties of a wheel-turning monarch?
Well then, my dear, relying only on principle — honoring, respecting,
and venerating principle, having principle as your flag, banner, and
authority — provide just protection and security for your court, troops,
aristocrats, vassals, brahmins and householders, people of town and
country, ascetics and brahmins, beasts and birds. Do not let injustice prevail in the realm.
DN 26

Therefore, while a monk cannot directly instruct a layperson to engage in any type of killing, a monk can directly instruct a layperson of a duty to protect their society. If the layperson chooses to engage in killing to protect their society; that is the choice of the layperson (and is unrelated to the advice of the monk).
For example, I only once listened to a speech by the Burmese 'terrorist' monk Wirathu and I never heard Wirathu transgress the monk's Vinaya (even though I did not personally agree with the underlying intent of his speech).
Monks do not have any country to defend. But laypeople have a country to defend. Many of these laypeople consider themselves to be Buddhists and want to live in a country with a culture that is influenced by Buddhism. They don't want to live a country influenced by Judaism (such as in Palestine) or Wahhabism (such as in Saudi Arabia). They want to live in a Buddhist country, where there is metta,  patience &amp; monks.
If Islam or Christianity, for example, ruled every country, the Buddhist religion may become extinct. History shows Christianity eliminated every religion it had power over and, under the (originally pluralistic) Islamic Empire, eventually, after about 500 years, Buddhism became extinct (when Turks and then Mongols took over the Islamic Empire).