"The reason the European debt crises is so serious is because the adoption of the euro means that no individual contry can print their own money to avoid default."
It's more because each individual country issues bonds. The ECB can't issue debt.
I am not sure I agree. The primary difference between pre and post EURO Europe is that, individual EURO countries no longer control their own currency. In times of economic crisis, countries can manipulate their currencies to make their economies more competitive internationally, and/or inflate their way out of a debt crisis. Despite what the media is saying, the U.S. is not in a debt crisis, we have many tools at our disposal to prevent default, including currency manipulation. The EU on the other hand has a handful of countries that are in serious jeopardy of defaulting.
It's more because each individual country issues bonds. The ECB can't issue debt.