After the Russian blunder in Ukraine, Russia is incapable of successfully invading Poland, for years to come.
In 2020 Polish commanders played a war game which resulted in Russia and Belarus reaching the line of Vistula in 5 days (but still not taking Warsaw yet).
Now we know that Polish commanders who played Russians used the assets and capabilities we believed for Russia to have, not the ones it actually has.
Russia is undoubtedly able to attack Poland with missiles. For this, we have no good response, at least as of yet. Even the two Patriot batteries purchased in the US but not yet delivered to Poland (there are however two American-owned Patriot batteries in Poland instead) won’t protect the whole Poland from Russian missile strikes. We need multilayered anti-missile defense system. We try to build it (not to produce it but to build it from the solutions purchased abroad) but it will take years. It still won’t be THAAD or the Iron Dome though.
We have 48 F-16 fighter jets so after delivery of 32 purchased F-35 we should be able to defend ourselves against Russian aircraft – unless they will try to swarm Poland and to win the air dominance by sheer numbers. For this, we should purchase F-15 and it is very clear now.
Our coastal defense should be able to destroy Russian warships on the Baltic Sea thanks to the excellent, Norway-produced Naval Missile Strike mobile missile launchers. The Russians don’t have any serious defense against such missiles.
There is however still a possibility of Russia using tactical nuclear warheads against Poland. We were banned by our Western allies from developing our nuclear weapons, so we don’t have any deterrent against Russia. The question is, would the US be ready to respond in kind against some Russian targets? That is an open question.