***Absolutely not! Life is sacred and cannot be tampered with. No one has any right to end another person’s life. This kind of thinking is actually very demoniac and is a symptom of modern day agnostic society, that comes from people who know nothing about the laws of mature and the laws of God. Non believers will put forth so many arguments, so many theories, many of which may appear based on reason and practicality. But we should know clearly that all such thoughts or ideas when not based on guru, sadhu and sastra, are but mental speculations meant to destroy the world.
This is all explained in the essential teachings of the Bhagavad-gita. People who think in this way are constantly changing their policies and introducing new laws. We should therefore know the basic laws as presented in the sastra and explained further by our various acaryas. Government leaders are enacting policies trying to establish and determine when it is acceptable to end life in the womb due to various factors as you mention above. The fact remains that from the moment of conception, the embryo
within the womb is indicating the presence of a spirit soul and no one has any right to terminate pregnancy or do an abortion based on such reasoning. I hope this is a bit more clear.
*** In every society there must be the ksatriya element. We also accept and recognize this and that is actually part of varnasrama dharma, what we call ksatriya dharma. The basic principles of ksatriya dharma in a Vedic environment is based on acceptance or rejection of the principles of dharma. Wars and hence killing can and must be done based on the acceptance or non acceptance of the principles of dharma.
Some times this does become complex and as we see in the case of the Mahabharata history, even among devotee Vaisnavas, because Bhismadeva and Drona were serving in the court of the Kauravas, when the war became inevitable, although they were devotee of Krishna and friends of Arjuna, due to social alliance and duty for the Kauravas, they had to fight against the Pandavas, they had to fight against Krishna Himself.
So war and fighting is present and authorized when based on principles of dharma. That is a very deep and involved science and can only be properly understood and applied under the guidance and direction of qualified brahmanas. The great personalities like Vidura, Drona and Bhismadeva have giving many moral instructions in this respect and we should learn these as well. One important book I have beens studying recently and from which I have compiled a course call “DHARMA SHASTRI” is based largely on the book called “Kautiliya Arthashastra”.