This is bigger than Ukraine. Trump and Le Pen can say publically whatever they want in order to get voters to support them, but at the end of the day this is about Taiwan, and even they know this. Because if China isn't delivered a strong message that the West is both willing and capable of supporting a weaker nation against a much more powerful one, then China will just invade Taiwan and then corner the world electronics market, among other things as well, and this will affect the West's economy as well as credibility a lot more than having to spend money in Ukraine.
Trump and LePen are not idiots. They know this.