ATHENS — As the world watches with the bated breath normally reserved for the larger hurricanes before they make landfall, a 40-mile-long Russian army convoy crawls toward Kiev and the question is not only when will it pounce, but how did it stall? 

The answer lies not only with the Kremlin’s calculations and reported miscalculations, but also with Whitehall, which has decisively if under the cloak of night taken on the role of chief supplier of arms — and maybe more — to the Ukrainian army. 

The British contribution to Ukraine’s war effort against Vladimir Putin increasingly emerges as both resolute and predating the EU’s more widely publicized push to assist Ukraine by means more robust than economic sanctions against its Russian adversary.  “The United Kingdom, where possible, is comprehensively leaning in to help the Ukrainians defend themselves,” the British defense secretary, Ben Wallace, told London’s Telegraph newspaper in an interview yesterday. 

The plain-speaking 51-year-old Conservative minister said that one of the things “I am glad we have done — we’ve done it since 2015 — is Operation Orbital, which was the capacity building of the Ukrainian forces … we’ve strengthened our intelligence relationships and our leadership relationships.” With characteristic British understatement, he added: “Those [relationships] are well-established, is what I’d say.”

Mr. Wallace spearheaded a donors’ summit on February 25 that according to Politico garnered pledges by 25 nations to send weapons and other military aid to Ukraine, “placing the British government at the forefront of the historic resupply effort.” He said that particularly useful among the weapons making their way overland into Ukraine are shoulder-launched Next Generation Light Anti-Tank missiles, and hinted  that these single-fire weapons have been helping to “pick off” Russian tanks toward the head of the long convoy. 

The Daily Mirror reports that President Putin “underestimated Ukraine’s air defenses, which have remained well-hidden and efficient, bringing down a staggering 44 warplanes.” While it is unclear what role, if any, weapons from Britain have had in downing Russian planes as well as denting Russian tanks, the general picture is that Britain has President Zelensky’s back. 

The intelligence relationships Mr. Wallace evokes may already be bearing fruit on the battlefield, particularly outside Kiev, where he says that Russia’s communications are so bad that its soldiers “are using everything they can to communicate on the Russian front line. And of course, that makes you deeply vulnerable.” This makes it highly likely that Ukrainian soldiers are gaining access to intercepts of Russian forces “communicating via phone calls due to poor radio equipment.” 

Moral support from Downing Street has not been in short supply, either. “It’s Day Ten of a plan that I think President Putin and his military leaders thought would take two or three days, maybe four, based on an arrogant assumption that they will all be welcomed as liberators,” Mr. Wallace told the Telegraph. 

The chief of Britain’s defense staff, Admiral Sir Antony Radakin, has said that Russia has “got itself into a mess” with the invasion of Ukraine that is “not going well.” Admiral Radakin, who is in effect the head of the British armed forces, told the Times of London yesterday that Russia’s lead forces have been “decimated” in Ukraine and it is not inevitable that it will succeed in taking over the country.