You can easily keep Wikipedia around - burn it on archive BDs(M-Disc), they are easily hidden, can take the whole Wikipedia in one disk and basic information is extremely valuable in an oppressive regime. Then do the same for a collection of E-Books based on what is most likely to be banned/what the right wing does take the biggest offence on. And what aids you the most in either getting out or resist.
Using archive BDs(M-Discs) is important as regular storage devices can easily be detected due to their metallic contents and they degrade within years. M-Discs are far more resilient and can be almost as easily hidden.
Technically the EU already is an defence organisation (Lisbon accords), even with a stronger mutual assistance clause than NATO. What is different is that there is no integrated command structure. But that is currently rapidly changing, Germany and the Netherlands already are fully integrated (more than NATO standards are), the Baltics are making great progress.
There is at least a chance