Tánaiste Leo Varadkar has said Ireland will have to increase military spending over the coming years.
He says the country needs to have the ability to effectively patrol seas and skies.
He says despite neutrality, Ireland cannot assume it is under no threat of attack.
"The assumption that we've made, for 70 years now, is that nobody would attack us because we're a country that's neutral militarily.
"Ukraine was neutral militarily, it wasn't part of any military alliance.
"It was attacked because it was politically part of the West, or at least wanted to be politically part of the West.
"And we make the assumption that even if we are attacked, the British and the Americans will come and save us anyway.
"And I'm not sure that's the kind of assumption a sovereign country like ours should make".
He adds: "If anything, this attack on Ukraine should be a wake-up call for all of us to defend our system, and be willing to defend it.
"A system worth building is worth defending, if the European Union was worth building it's worth defending.
"And if our independence was worth securing, it's also worth defending".