OMG, the shield requires personnel to run it. So when you invade a country, you need to take into account there might be casualties among US serviceman. Now thi

OMG, the shield requires personnel to run it. So when you invade a country, you need to take into account there might be casualties among US serviceman. Now this is really risky. Another point, that's pretty simple: with the shield you can nuke Ruskies and they can't nuke you. Quite a difference compared to the current situation which is a direct result of Obama being soft on Putin.