For Gundbert Scherf — the co-founder of Germany's Helsing, Europe's most valuable defense startup — Russia's invasion of Ukraine changed everything.

Scherf had to fight hard to attract investment after starting his company — which produces military strike drones and battlefield AI — four years ago.

Now, that's the least of his problems. The Munich-based company more than doubled its valuation to $12 billion in a round of fundraising last month.