National ID cards are an outmoded idea that do not work, especially in these circumstances. Neither France nor Spain nor Germany have ever arrested any known terrorist based on his ID (and these countries have had ID's for years). In fact when they arrest terrorists, they find in something like 100% OF CASES that the terrorists have had one if not many fake ID's.

In fact, it is widely known that French police have abused the national ID for years by using it as a n excuse to harass and even jail anyone they want for any reason (no ID? 24 hours in prison if they so wish)