Russia has made Trump look weak

It's been a confusing week.

The Monday gathering of European leaders and Ukraine's president with Donald Trump at the White House was highly significant. Ukraine latest: Trump changes tack The leaders went home buoyed by the knowledge that they'd finally convinced the American president not to abandon Europe.

He had committed to provide American "security guarantees" to Ukraine. The details were sketchy, and sketched out only a little more through the week (we got some noise about American air cover), but regardless, the presidential commitment represented a clear shift from months of isolationist rhetoric on Ukraine - "it's Europe's problem" and all the rest of it.

Yet it was always the case that, beyond that clear achievement for the Europeans, Russia would have a problem with it. Trump's envoy's language last weekend - claiming that Putin had agreed to Europe providing "Article 5-like" guarantees for Ukraine, essentially providing it with a NATO-like collective security blanket - was baffling.

Russia gives two fingers to the president And throughout this week, Russia's foreign minister Sergei Lavrov has repeatedly and predictably undermined the whole thing, pointing out that Russia would never accept any peace plan that involved any European or NATO troops in Ukraine. "The presence of foreign troops in Ukraine is completely unacceptable for Russia," he said yesterday, echoing similar statements stretching back years.

Remember that NATO's "eastern encroachment" was the justification for Russia's "special military operation" - the invasion of Ukraine - in the first place. All this makes Trump look rather weak.

It's two fingers to the president, though interestingly, the Russian language has been carefully calibrated not to poke Trump but to mock European leaders instead. That's telling.

Read more on Ukraine:Trump risks 'very big mistake'NATO-like promise for Ukraine may be too good to be trueEurope tried to starve Putin's war machine - it didn't go as planned The bilateral meeting (between Putin and Zelenskyy) hailed by Trump on Monday as agreed and close - "within two weeks" - looks decidedly doubtful. Maybe that's why he went along with Putin's suggestion that there be a bilateral, not including Trump, first.

It's easier for the American president to blame someone else if it's not his meeting, and it doesn't happen. NATO defence chiefs met on Wednesday to discuss the details of how the security guarantees - the ones Russia won't accept - will work.

European sources at the meeting have told me it was all a great success. And to the comments by Lavrov, a source said: "It's not up to Lavrov to decide on security guarantees.

Not up to the one doing the threatening to decide how to deter that threat!" The argument goes that it's not realistic for Russia to say from which countries Ukraine can and cannot host troops. Would Trump threaten force? The problem is that if Europe and the White House want Russia to sign up to some sort of peace deal, then it would require agreement from all sides on the security arrangements.

The other way to get Russia to heel would be with an overwhelming threat of force. Something from Trump, like: "Vladimir - look what I did to Iran...".

But, of course, Iran isn't a nuclear power. Something else bothers me about all this.

The core concept of a "security guarantee" is an ironclad obligation to defend Ukraine into the future. Future guarantees would require treaties, not just a loose promise.

I don't see Trump's America truly signing up to anything that obliges them to do anything. A layered security guarantee which builds over time is an option, but from a Kremlin perspective, would probably only end up being a repeat of history and allow them another "justification" to push back.

Read more from Sky News:Inside the ISIS resurgence10 years since one of UK's worst air disastersHow Republicans are redrawing maps to stay in power Image and reality don't seem to match Among Trump's stream of social media posts this week was an image of him waving his finger at Putin in Alaska. It was one of the few non-effusive images from the summit.

He posted it next to an image of former president Richard Nixon confronting Soviet leader Nikita Khrushchev - an image that came to reflect American dominance over the Soviet Union. That may be the image Trump wants to portray.

But the events of the past week suggest image and reality just don't match. The past 24 hours in Ukraine have been among the most violent to date..