Israel’s status as the Start-up Nation is clear, but may not be secure for the future, Cisco Systems CEO John Chambers told a Calcalist event in San Francisco.“When I talk about Israel, I’m talking about one of my favorite countries in the world. But the fact that it is a start-up hub now doesn’t mean it will continue that way,” Calcalist quoted Chambers as saying. “I’m optimistic, but I also want the ones sitting in the room to not be comfortable.”Chambers, whose company has acquired 12 Israeli startups through the years and has significant operations here, pointed to France as an example.Paris, he said, used to be a place to enjoy food, not do business. Forward-thinking policies have changed that.One of the big challenges Chambers cited was the need to integrate ultra-Orthodox Jews and Arabs into the workforce, a challenge the Bank of Israel has cited as one of the most important for Israel’s medium and long-term economic health.He also cited the need for STEM (Science, Technology, Engineering and Mathematics) education to help train the next generation of engineers.On his last visit to Israel in June 2013 Chambers said that Israel was on track to become the first digital state if it invested in the right infrastructure. Chambers isn’t the only executive from a hi-tech multinational to sound the alarm on Israel’s future.Yoram Yaacovi, the general manager of Microsoft Israel R&D Center in Herzliya, said that the country was “running out of geeks,” noting a shortage of engineers. Former Intel Israel president Mooly Eden regularly warned that the country was becoming complacent instead of investing in the future.