Depends on how you define peacetime (and if you assume he meant "high treason", because "regular" treason always exists). If you use the narrowest definition (as in, no hostilities, potential or otherwise, anywhere, at all), then you could argue that. However, it's hard to achieve this kind of peace. From western EU's POV, for example you could probably argue that they are at this kind of peace. Their neighbors are friendly and they're not at odds with any country to the point it could threaten national security. From Poland's POV, you could not, relations with Russia are too strained and it is potentially endangered. US also has quite a few enemies, and it can hardly be said "there's no treason" now. An information stolen and traded off to one of many anti-US countries could have devastating effects. There's no treason in peacetime, but it's no peacetime right now, either.
Note that I was speaking in general terms in my previous post. The situation now actually falls in "near-wartime" category, just like Cold War did. The situation in Ukraine is ugly, Middle East is still stirred up, and North Korea isn't sleeping, either. It's easy to preach about morality, state affair transparency and value of human life from a cozy seat in peaceful Germany, but sometimes, extreme situations can happen, and there better be proper legislation for it, so that the government doesn't end up running like headless chickens when it hits the fan... Or at least, so that there can be someone that doesn't.