Conservatives are promising a Britannia shield. Before anyone gets carried away, it is worth paying close attention to the lessons from Ukraine and Israel on what such a shield can and cannot do. Is it possible to build an Israel-style protective shield around Britain, combining anti-drone and anti-ballistic missile capabilities? Yes. The technology exists. Whether a missile flies from a launch site in the middle of Siberia or a drone from a tanker off our coast, there are systems that can neutralise it. Israel's experience shooting down Iranian ballistic missiles outside the atmosphere proves the point. But here is the reality, and it is dark. Both Ukrainian and Israeli experience tells us that any shield, however advanced, can be overwhelmed. If more targets attack simultaneously than the shield can handle, it starts missing. A shield is a colander. The only question is how wide the holes are. We have watched this happen. Ukrainian defences built around Patriot and Israeli layered systems have both been saturated in recent attacks, whether Russian ballistic missiles against Ukraine or Iranian ones against Israel. A shield contains the damage. It does not bring it to zero, and it does not prevent it. Then there is the economics, and this is where the picture gets worse. Jet-powered drones are cheap. Ballistic missiles like the Oreshnik are not cheap, but they are far cheaper than the interceptors needed to take them out. Rocket technology is decades old. The science required to intercept a missile accelerating almost vertically onto its target massively outstrips the cost of building the missile itself. The asymmetry is brutal. Israel understood this. When attacked, Israel and the US struck the launch sites. A shield that shoots down arrows does not stop the archer from firing. It does not deter him either. The archer thinks twice only when he knows the response will come back in kind, and then some. Britain suspended its own conventional ballistic missile capability on the assumption that Trident, our only ballistic missiles, would deter everything. It will not. If Russia attacked us with a conventionally armed Oreshnik, we would not respond with nuclear weapons, because that triggers nuclear war. The nuclear shield deters nuclear attacks. Conventional attacks demand conventional responses of the same kind, and right now we do not have them. So yes, the Britannia shield is a good idea. Strengthening our aerial defences against the threats we see deployed against Ukraine and Israel is necessary and it will save lives. But the only way to genuinely minimise the chance of being attacked is to develop our own ballistic missile and long-range strike capabilities. Abundance of cheap metal tubes that can also fly and cause carnage. That is what makes an adversary think twice.

Newsflash: @reformparty_uk is not a political party. It is a grievance campaign with a bank account. That is the sad truth. No coherent philosophy. No intellectual foundation. No vision that paints the future. No talent to build one. Just resentment, packaged and sold. Look at @RobertJenrick's latest stunt. "Kensington Kemi." Attacks on his former boss @KemiBadenoch. Stunts dressed up as strategy. Watch it closely and you see the whole rotten model: Reform chasing every tactical opportunity to be the anti-Tories. It doesn't matter if it makes them sound like Corbynistas. It doesn't matter if their policies start to resemble Dilma Rousseff's Brazil - handouts dressed as economics. It doesn't matter if they cosy up to the blood-and-soil types stoking racism against @KemiBadenoch. If a position is anti-Tory, they will take it. That is the entire proposition. Grievance and resentment. And let me be clear: the grievance against the previous Conservative government is real, and it is justified. I share it. I believe, most party members share it. But it is now up to Kemi and her team - whose ratings are consistently improving - to convince right-leaning voters that the Conservative Party is renewed, competent, and will govern as a truly right-wing party that turns Britain around. That is the fundamental distinction. The Conservatives are regenerating. Reform is chasing its own tail. Because deep down, Reform knows it doesn't have the talent to become a proper ideology-based force for good. So it must be the mirror image of the Tory party - forever defined by what it opposes, never by what it builds. Now look at the actual work. The Conservative policy programme starts with proper diagnosis - what is actually wrong with Britain - and builds a package with the end in mind. Deregulation. Ripping up red tape. Genuine energy security, not environmentalist dogma. Scrapping taxes that strangle productive activity. The target: the productivity slump that has plagued this country for over a decade and driven GDP per capita into the ground. The result? More innovation. More growth. More jobs. A flywheel that makes every single one of us wealthier. And Reform's answer to all that? A thousand quid off your tax bill. A bribe, plain and simple - no different to Trump's five-grand promise in America. It has nothing to do with growth. Nothing to do with productivity. It is redistribution dressed up as reform. Socialism with a Union Jack wrapped round it. That tells you everything about the state of them. Incredibly desperate. Sitting on a massive donation pot, pouring it all into campaigning - but campaigning against, never for. And no amount of slick campaigning can compensate for bad ideas. Good ideas require homework. Hard work. Starting with the end in mind and working backwards. There is only one party in British politics doing that work today. The Conservative Party.