To be even-handed between oppressor and the oppressed, between the expropriator and the dispossessed is always to take the side of the former against the latter. Oppression and expropriation usually involve violence, particularly in the context of colonialism.
The principle of self defence is something that is in both international law with regard to nation states: a state is allowed to fight against the invasion of its territory for instance. It is installed domestic law: if I pick up a knife and stab someone who is trying to kill me with an axe I commit no offence.
The reason for this principle and the reason that it represents justice is that you should not be required to suffer injury that someone else is deliberately inflicting on you. From the other point of view there is an answer to those who wish to avoid force being used in self-defence against them: do not use violence yourself in the first place.
Most mainstream or bourgeois commentators would have little problem with the principle of self-defence as it is written into international or domestic law. Where they will go flaky is with the idea that people oppressed by colonialism or imperialism should be able to resist the violence that is visited upon them.
In practice of course principles such as self-defence are not applied evenly: nation states allied with the West are given huge leeway to do what they like in keeping the world safe for imperialism and the corporate interest. Examples would be Nigeria and Colombia. Often of course “self -defence” is extended to cover acts of simple thuggery such as the operation of death squads in Colombia.
On the other hand when the oppressed fight back a harder stance is taken. In Gaza, the colonialist’s can launch terror attacks on civilians: civilians who cannot find refuge in shelters nor by flight to safe areas. On the other hand any strike back is condemned out of hand.
Ah but we do not say that! We condemn both Israel and Hamas for being reactionary and using violence!
Various liberal lefties come out with this. This sounds reasonable but is not. Israel, or any oppressor does not need to use any violence. It would be left in peace if it submitted to any kind of just settlement: but of course it cannot do this for a variety of reasons that can be summed up in its continued commitment to the Zionist project. To be fair of course Israel has been used by the puppet masters in Washington DC down the decades as a threat to the Arab regimes. Zionism creates the regional instability that cause the Saudi rulers in particular to cling to the apron strings of the US. It is difficult to gauge how far a fair minded liberal government would be allowed to go in getting a fair settlement that allowed the Palestinians to live freely and equally with Israelis.
The Palestinians whether in Gaza, the West Bank or in exile do not have this option. Giving up resistance will be taken as a sign weakness, a green light for further expropriation and immiseration.
Looked at in terms of the political dynamics the same conclusion is reached. Many people may in good faith adopt a position of condemning both sides equally. However remember that the imperialists will latch onto anything as an excuse to impose their rule. Witness the noise about the rights of women in Afghanistan and the silence about the rights of women in Iraq. For example sexism and homophobia are social problems that need to be addressed politically.They are not something that should be used as a cover for the violent expropriation involved in imperialist subjugation.
If you do not understand this you will always find that the criticism of imperialism fades away while the criticism of those resisting imperialism is amplified.