We can't. The radical pro-small-state finance minister fights tooth and nail against any additional debt in order to obey the holy debt ceiling that a bunch of idiots wrote into the constitution about a decade ago because they didn't understand the difference between a national budget and a company budget.
There is this weird idea in some circles that national budgets are endless debt pits which you just can create any amount of money from for just about any reason. This obviously is incorrect as a blanket statement - it only has some time-constrained credibility for relatively rich countries with a somewhat good future ahead of it. If your economy is weak and your outlook is bad, no-one is going to lend your country money to put the national budget into the red even more - just ask Greece what happens next.
Germany has had a relatively strong economy and good growth in the past, which allowed us to spend a bit more lavishly. But with our economy about to break down in the next 20-30 years and our population shrinking massively (worse: with employee-age population shrinking even more), this is no longer the case.
Insofar, I think it is prudent to keep expenses under control. Of course, you can't play international moral police and cause massive inflation if you do so. Which is where Berlin fails right now.
We can't. The radical pro-small-state finance minister fights tooth and nail against any additional debt in order to obey the holy debt ceiling that a bunch of idiots wrote into the constitution about a decade ago because they didn't understand the difference between a national budget and a company budget.