Russian President Vladimir Putin has called on the country's top brass to deliver a drastic upgrade of the armed forces in the next three years to fend off attempts from abroad to ‘tip the strategic balance’ in the world. In his address to Russia's defence ministry and top military officials, Putin said on Wednesday that Russia is witnessing ‘insistent attempts’ to tip the balance and complained about US attempts to set up a new missile defence system. ‘Geopolitical developments call for our response to be well-calculated and quick,’ the Interfax news agency quoted him as saying.