Two threats to Bitcoin: Quantum Computing and Mining farm seizures - what new BIPs are needed before it is too late?
How resistant is bitcoin blockchain against physical attacks? Contrary to other consensus mechanisms, Bitcoin's PoW model is dependent on massive Mining Farms with tons of ASIIC hardware. These farms are known to everyone, especially the government of respective country.

Bitcoin's protocol is designed to adjust to increases and decreases in network hash rate. There is a difficulty adjustment for this purpose. If a number of mining farms all went offline in an instant it would result in higher confirmation times until the difficulty adjustment kicked in two weeks later. Although disruptive in the short term it would have no greater impact than that.

The bitcoin network is not using signatures or encryption methods that are especially suited against quantum computer attacks. Especially Bitcoin's ECDSA and the PoW mining process would become easily vulnerable with quantum computers.

The Bitcoin protocol is using elliptic curve cryptography as are all internet security protocols and banking security applications. As Pieter Wuille states here:

Quantum resistant signature algorithms do exist, but they all rely on very large signatures - which may make them unfeasibly expensive for purposes like Bitcoin.