Wartime Actions vs. Normal Standards

There was an Irish organization that was looking to form an uprising during World War One. Its motives were found out, and its leaders executed or jailed for the remainder of the war. I find it interesting that such drastic measures were taken. It is logical that during a war anyone who is against you is an enemy that should be treated as opposing militia, but it seems contradictory of diplomatic values to react so violently. The group hadn't received any form of weaponry, they were not trained, they hadn't attacked anyone. In essence they were still civilians, and yet because of the war they were attacked and treated as an armed force. I think that perhaps the action was necessary, though in a peacetime situation I wonder, would Britain have earned the disapproval of the rest of the democratic world for an attack on civilians merely trying to voice an opinion?

Was World War One Truly Amidst an Era of Advancement?

Technological advancements leading to WWI made war on an international scale possible. Communication allowed nations to forge alliances, it also allowed growing armies to stay united and organized. Advances in machinery had the possibility of taking 20th century militia into a new era of warfare, but they didn't. Why with all the technological improvements didn't military planning change? The war proved static because incredible new weaponry was coupled with outdated and ineffective tactics.

This provokes the question, Why? There were many renouned military planners during this time and none of them was innovative enough to come up with a solution. It's hard to discern an explanation for this, perhaps the vigor of world war came as a surprise, or planners didn't want to believe times were changing, in either case a lack of adaptation in battle plans lengthened an extremely deadly war.