The plan marks the first broad update since 1995, when a dismantling of federal civil defence structures was advocated as security policies were eased in the wake of German reunification.
But the 69-page document warned that “the security policy environment has changed again”.
Critics however accused Chancellor Angela Merkel's “grand” right-left coalition of scaremongering ahead of key state elections in September.
And the population took to social media to deride the strategy, with the hashtag #hamsterkaeufe (squirrelling away) and photos of the furry rodent widely circulating on Twitter.
Interior Minister Thomas de Maiziere rejected the criticism, saying that “while we all hope that we will be spared from major crisis, we must be prepared” should disaster strike.
“It's only responsible, sensible and appropriate to make cool-headed preparations for a catastrophe scenario,” he said, stressing that “every country in the world does that”.
He also challenged charges of electioneering, arguing that the strategy is the result of a long reflection process that had been in 2012.
While acknowledging that “an attack on German territory requiring conventional defence is unlikely,” Europe's biggest economy should be “sufficiently prepared in case of an existence-threatening development in the future that cannot be ruled out,” the strategy document said.
“The proliferation of weapons of mass destruction and their delivery systems, conflict driven by terrorist means and cyberspace attacks can be a direct threat to Germany and its allies,” it said.
The plan makes civilian backing of troops a priority while advocating making buildings more resilient and increasing capacity in the healthcare system.
It also encourages people to stockpile sufficient food for 10 days, and water to last five.
Haunted by its Nazi past, Europe's most populous country has for decades been particularly cautious about military issues.
But this year it set out a new roadmap outlining Germany's ambition to assume a bigger defence role abroad, within the frameworks of NATO and the European Union.
A string of attacks at home in July – including two claimed by terrorist group Isis – has also sparked a fierce debate about internal security.
The defence ministry is looking at training the military to respond to major terror assaults, while Interior Minister Thomas de Maiziere last week announced tough new anti-terror measures including a controversial proposal to strip jihadist fighters of their German nationality.